September 9, 2017

TRUWIZ 118
trusciencetrutechnology@blogspot.com

Volume 2017, Issue No.9, Dated: 9 September 2017

[Initiated by Prof. Dr. K. Lakshmi Narayana]

In Memory of

Late Professor Kotcherlakota Rangadhama Rao

D.Sc. (Madras). D.Sc. (London).

(Birth on 9 September 1899 Early Morning, Berhampur

Demise on 20 June 1972 at 9h09m at Visakhapatnam),

at his residence, Narasimha Ashram, Official Colony,

Maharanipeta. P. O., Visakhapatnam 530002.

[Mrs. Peramma Rangadhama Rao demise on 31 Dec 1971 around 10 AM.]
TRUWIZ-118

Q1. Distinguish between centre of Mass and Centre of Gravity. Centre of mass is a point at which whole mass of the body is concentrated. It does not depend on the acceleration due to Gravity. It always present inside or outside the body. In case of small bodies Centre of Mass and Centre of Gravity are roughly the same. Centre of Gravity is a point where the whole weight of the body is concentrated. It depends on acceleration due to Gravity. It is always present inside the body. In case of big bodies Centre of Mass and Centre of Gravity different. Examples Mountains, Big Buildings etc. Nearby topography perturbs gravity measurements upward due to mass, mass excess above the station (nearby hills) or due to mass deficiency below the station (nearby valleys). Δg=G (dm cosθ) / (r^2 +z^2) where r and z are the horizontal and vertical distances to dm, and θ is the angle to the vertical. The terrain correction is always positive . Integrating over a sector gives: Δgr=G⍴φ {(√(r^2+h^2) – r1) – (√(r^2+h^2) - r2) where r1 and r2 are the inner and out radii, h is the height, φ is the sector angle. The terrain correction is computed using: Average gravity on the Earth’s surface is about g=9.8 m/s^2, and varies by ~5300mgal (about 0.5% of g ) from pole to equator. (1mgal=10^-5 m/s2) Gravity anomalies are local variations in gravity that result from topographic and subsurface density variations, and have amplitudes of several mgal and smaller. Superconducting Gravimeter: Suspend a niobium sphere in a stable magnetic field of variable strength. Sensitivity: 1ngal. A joint mission of NASA and the German Aerospace Centre, has been making detailed measurements of Earth’s Gravity field anomalies since its launch in March 2002. Gravity is determined by mass. By measuring gravity anomalies, GRACE shows how mass is distributed around the planet and how it varies over time. GRACE data have provided a record of mass loss within the ice-sheets of Greenland and Antarctica. Greenland has been found to lose 280 ± 58 Gt of ice per year between 2003 and 2013, while Antarctica has lost 67± 44Gt per year in the same period. These equate to a total of 0.9 mm / y of sea level rise. GRACE data between 2003 and 2013 to conclude that 21 of the world's 37 largest aquifers "have exceeded sustainability tipping points and are being depleted" and thirteen of them are "considered significantly distressed." The most over-stressed is the Arabian aquifer system upon which more than 60 million people depend for water. GRACE data also contribute to fundamental physics. They have been used to re-analyse data obtained from the LAGEOS experiment to try to measure the relativistic frame dragging effect. The ranging system is sensitive enough to detect separation changes as small as 10 micrometres (approximately one-tenth the width of a human hair) over a distance of 220 km. As the twin GRACE satellites circle the globe 15 times a day, they sense minute variations in Earth's gravitational pull. When the first satellite passes over a region of slightly stronger gravity, a gravity anomaly, it is pulled slightly ahead of the trailing satellite. This causes the distance between the satellites to increase. The first spacecraft then passes the anomaly, and slows down again, meanwhile the following spacecraft accelerates, then decelerates over the same point. By measuring the constantly changing distance between the two satellites and combining that data with precise positioning measurements from Global Positioning System (GPS) instruments, scientists could construct a detailed map of Earth's gravity
a. anomalies b. perturbations c. changes d. disturbances

Q2. Friday, 6 January 2017: at ISC 2017 Tirupathi: presented paper entitled “Water in Universe with Gravitons and its double lone-pair electrons at an apex distance of 1.4 Ȧ". trusciencetrutechnology@blogspot.com: Surprising that the present or the ancient devoted people in India, pray four times a day, practised in all the states by people residing in them, with Water, with the conviction that Water alone can transform them to the unseen world of universe. Water as a medium they by concentration during the daily recitations, could possibly engulf the entire universe! I found a Brahmin in Theosophical Lodge of Tamil Nadu, practising the daily recitation of the MANTRAS, could engulf the entire universe. Quasar Contains Largest Water Reservoir In The Universe: Sept 24, 2011: The Huffington Post: Double pair electrons share in the middle the Graviton, as per my model considerations. This positioning of the individual gravitons helps to distribute the entire galaxy spread, water distribution. Several water molecules, along with their associated gravitons and the lone-pair electrons, may assemble to augment the entire spread of the expanse of the water distribution in the galaxy, each holding a graviton. This is totally a new look of the galaxy spread, with water molecules and the four electron embedded Graviton. Double pair electrons share in the middle the Graviton, as per my model considerations. This positioning of the individual gravitons helps to distribute the entire galaxy spread, water distribution. Several water molecules along with their associated gravitons and the lone-pair electrons may assemble to augment the entire spread of the expanse of the water distribution in the galaxy, each holding a graviton. This is totally a new look of the galaxy spread, with water molecules and the four electron embedded
a. Electrons b. Positrons c. Gravitons d. Water spread

Q3. The new equations of third order and fifth order both to describe the particles are enunciated. It involves in third order, all the momenta p1, p2, p3 of the particle and has a mass m term. It has the form m^3+m^2*a2+m*a1+a0=0 with the coefficients a2, a1 and a0 being elaborate functions of the momenta. This happens to be a subgroup {I, W, J, X} of a bigger Group G (S3). [Given earlier by squdder@du.edu]. The equation formulated by me, is given as -m*I + p1*W + p2*J + p3*X = 0, where m is the mass of a three dimensional space and involving the subgroup elements as operators. The extensive analysis, reveals the present equation with complex form and yields a real solution as well. The cubic mass term is very distinct and, unlike the Dirac equation, reveals new mathematics. Further, I designate U=p1; V=p2; Q=p3; B=p0; A=E; as the other possibility of the description for the massive particle M in a 5D space-time group. We get -M*I + a*A +b*B + u*U + v*V + q*Q = 0. Here M becomes the mass of a five dimensional space-time particle. The addition of an energy expression E and the momentum p0, enlarges the present model. Details are explicitly be given. The present work describes the third order description of the particle with mass m and, as well the fifth order description of particle with mass M explicitly. Graphs given presented for both type of particles at the ISC 2017 on the 5 January between 2:30 PM to 6 PM at the Department of Mathematics, Tirupati University, Tirupati. The University was established by Late Prof K R Rao D.Sc.(Madras) D.Sc.(London) in the year 1954 as a special officer appointed by the then Chief Minister, Tanguturi Prakasam Pantulu Garu who was displaced by a no confidence vote. Prof K R Rao, hardly held office for about six months as a special officer, and remarkably completed the formation of The Sri Venkateswara University, with sites selected for the new departments, and about 15 Professors of eminence appointed, with the orders dispatched to
a. Professor b. Academicians c. Officers d. them

Q4. Implications from $B \to K^{*} ℓ^{+} ℓ^{-}$ observables using $3 {fb}^{- 1}$ of LHCb data: Rusa Mandal and Rahul Sinha, Phys. Rev. D 95, 014026, 2017: The decay mode $B$ $\to$ $K$ **$^{*}$ $ℓ$ $^{+}$ $ℓ$ $^{-}$ results in the measurement of a large number of related observables by studying the angular distribution of the decay products and is regarded as a sensitive probe of physics beyond the standard model (SM). Recently, LHCb has measured several of these observables using 3 ${fb}$ $^{-}$ $^{1}$ data, as a binned function of q $^{2}$ , the dilepton invariant mass squared. We show how data can be used without any approximations to extract theoretical parameters describing the decay and to obtain a relation amongst observables within the SM. We find three kinds of significant disagreement between theoretical expectations and values obtained by fits. The values of the form factors obtained from experimental data show significant discrepancies when compared with theoretical expectations in several $q$ $^{2}$ bins. We emphasize that this discrepancy cannot arise completely due to resonances and non-factorizable contributions from charm loops. Further, a relation between form factors expected to hold at large $q$ $^{2}$ is very significantly violated. Finally, the relation between observables also indicates some deviations in the forward-backward asymmetry in the same $q$ $^{2}$ regions. These discrepancies are possible evidence of physics beyond the**

a. FM b. QM c. SM d. DM

Q5. STARS FLUCTUATING:The Jan 7 AAS was told by Calvin College Astronomers in Michigan that a nondescript star in the Cygnus constellation will likely become one of the brightest objects in the sky. KIC 9832227 is actually not one star. It’s two. One is about the third of the size of our Sun. The other is roughly 40 per cent bigger. They’re orbiting each other so close that their superheated atmospheres are actually touching each other. New observations reveal the stars are in an accelerating death spiral, constantly winding faster and closer. At the moment, that orbit is once every 11 hours. After collision a new star would be born. ‘Tabby’s Star’ KIC 8462852 exploded out of obscurity in October last year when an amateur group of astronomers noticed, it was doing something extremely odd. It was flickering. Its brightness was changing by up to 22 per cent, a much greater degree than could be explained by any known possible cause. A separate look back at over a century of data also appeared to show it having dimmed by about 20 per cent in total. Over a period of 78.8 days, EPIC 204278916’s light fluctuated erratically by up to 65 per cent over 25 consecutive days. In the case of EPIC 204278916, its age could be something of a clue. Astronomers say it seems to be no older than 11 million years. And while it’s about the size of our own Sun, it probably holds only about half the
a. Shine b. Mass c. Angular Momentum d. Weight

Q6. Laws of Physics defied 17 Jan 2017:Increased impedance near cut-off in plasma-like media leading to emission of high-power, narrow-bandwidth radiation: M.S.Hur, B. Ersfeld, A. Nobel, H. Suk, D.A. Jaroszynski: Scientific Reports 7, Article Number 40034, 2017: We enhance the spectral density of radiation in a particular frequency band from a generally broad-band electric current, by embedding it in a simple meta-structure or a medium with a plasma-like permittivity. This can be arranged to increase the radiation impedance at a desired frequency, by taking advantage of the well-known fact that the radiation impedance Z=E/H, where E and H are electric and magnetic fields of radiation, respectively, becomes infinite at the cut-off frequency (i.e. H = 0) of a medium with a plasma-like permittivity, where typically ω² = c²k² + f(ω, ω_p) (ω_p is the plasma frequency). A current enforced under the cut-off condition (i.e. a pure current source) leads to the apparent non-physical situation of an ‘infinite’ radiation power according to Ohm’s law P = ZI². This implies that the steady state solution of H = 0 ceases to be valid. Instead, we discover that a monochromatic, continuously oscillating current source in a cut-off region generates a temporally growing and spatially diffusing electric field, which is a solution of the driven-Schrödinger equation. It is surprising that this behaviour has not been previously addressed, in spite of the cut-off being a universal feature of these media. Here we reveal that a specific frequency band (i.e. near the cut-off) is selectively boosted when driven by a broad bandwidth, few-cycle current source, just by immersing it in a medium with a plasma-like
a. splendour b. appearance c. frequency d. permittivity

Q7. MYSTERY WALL OF INDIA: Possibly between 900-1300 years Rajaputra Kings might have built with Ligo Bricks, the Great wall of India in the Vindhya Hills about 15 feet height extending over 80 km called by local people as Diwal. It has astounding rock cut images of Gods, Goddesses, Nagapratimalu, Lime stone constructed enchanting Lakes, etc innumerable attractions. Not certain when it was built, there are no evidences of the construction but has certain steps to climb up the wall at certain places. Places, of keeping the arms inside the walls, and to observe the enemies from a long distances exist. Nearby Bhimbetka has 30,000 years old rock hilly places of stay recognised by UNESCO heritage site. Jamnabai Khare, who’s lived in Gorakhpur for 60 of her 80 years, recalls seeing a Sinhavahini, a goddess astride a lion, which is now missing. Chaubey has a photograph of an intact statue of Kal Bhairav, an incarnation of Shiva (others are missing heads or limbs). “The image is all that remains, the idol was stolen last year.” Jamnabai Khare 60 years old, said that her father-in-law told her that Mahmud of Ghazni destroyed the kingdom.
a. kingdom b. empire c. royalty d. land

Q8. 30 January 2017: A “blue straggler”, feeds off its companion star by sucking out its mass and energy, causing its eventual death. The most popular explanation is that these are binary systems in which the smaller star sucks material out of the bigger companion star to become a blue straggler, and hence is called a vampire star. India's first dedicated space observatory, ASTROSAT, has captured the rare phenomenon of a small, 6-billion-year-old "vampire" star "preying" on a bigger celestial
a. fragment b. circulation c. body d. straggler

Q9. The material - atomic metallic hydrogen, was created by Thomas D. Cabot Professor of the Natural Sciences Isaac Silvera and post-doctoral fellow Ranga Dias. In addition to helping scientists answer fundamental questions about the nature of matter, the material is theorized to have a wide range of applications, including as a room-temperature superconductor. The creation of the rare material is described in a January 26 paper published in Science. Silvera and Dias squeezed a tiny hydrogen sample at 495 gigapascal, or more than 71.7 million pounds-per-square inch - greater than the pressure at the center of the Earth. At those extreme pressures, Silvera explained, solid molecular hydrogen -which consists of molecules on the lattice sites of the solid - breaks down, and the tightly bound molecules dissociate to transforms into atomic hydrogen, which is a metal. Among the holy grails of physics, a room temperature superconductor, Dias said, could radically change our transportation system, making magnetic levitation of high-speed trains possible, as well as making electric cars more efficient and improving the performance of many electronic devices. The material could also provide major improvements in energy production and storage - because superconductors have zero resistance energy could be stored by maintaining currents in superconducting coils, and then be used when needed. Compressed hydrogen transitioning with increasing pressure from transparent molecular to black molecular to atomic metallic hydrogen. The sketches below show a molecular solid being compressed and then dissociated to atomic hydrogen. Metallic hydrogen could also play a key role in helping humans explore the far reaches of space, as the most powerful rocket propellant yet discovered. And if you convert it back to molecular hydrogen, all that energy is released, so it would make it the most powerful rocket propellant known to man, and could revolutionize rocketry. Producing metallic hydrogen has been a great challenge to condensed matter physics. Metallic hydrogen may be a room temperature superconductor and metastable when the pressure is released and could have an important impact on energy and rocketry. We have studied solid molecular hydrogen under pressure at low temperatures. At a pressure of 495 GPa hydrogen becomes metallic with reflectivity as high as 0.91. We fit the reflectance using a Drude free electron model to determine the plasma frequency of 32.5 ± 2.1 eV at T= 5.5 K, with a corresponding electron carrier density of 7.7 ± 1.1 × 1023 particles/cm3, consistent with theoretical estimates of the atomic density. The properties are those of an atomic metal. We have produced the Wigner-Huntington dissociative transition to atomic metallic hydrogen in the laboratory.
  a. Space b. Laboratory c. Propellants d. Moon.

Q10. 26 Jan 2017: For most metals, the relationship between electrical and thermal conductivity is governed by the Wiedemann-Franz Law. Simply put, the law states that good conductors of electricity are also good conductors of heat. That is not the case for metallic vanadium dioxide, a material already noted for its unusual ability to switch from an insulator to a metal when it reaches a balmy 67 degrees Celsius, or 152 degrees Fahrenheit.  Could lead to a wide range of applications, such as thermoelectric systems that convert waste heat from engines and appliances into electricity. According to a new study led by scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and at the University of California, Berkeley, electrons in vanadium dioxide can conduct electricity without conducting heat.The findings, to be published in the Jan. 27 issue of the journal science,  could lead to a wide range of applications, such as thermoelectric systems that convert waste heat from engines and appliances into electricity. For most metals, the relationship between electrical and thermal conductivity is governed by the Wiedemann-Franz Law. Simply put, the law states that good conductors of electricity are also good conductors of heat. That is not the case for metallic vanadium dioxide, a material already noted for its unusual ability to switch from an insulator to a metal when it reaches a balmy 67C or 152F. Vanadium dioxide has the added benefit of being transparent below about 30C (86F), and absorptive of infrared light above 60C, 140F. But a team in the US has shown that this isn't the case for metallic vanadium dioxide (VO₂), a material that's already well known for its strange ability to switch from a see-through insulator to a conductive metal at the temperature of 67C(152F). Vanadium dioxide also has the unique ability of being transparent to around 30C(86F), but then reflects infrared light above 60 degrees Celsius (140F) while remaining transparent to visible light. It could even be used as a window coating that reduces the temperature without the need for
a. sub-zero temperatures b. air conditioning c. thermalization d. transparency.

Q11. 1 Feb 2017:9AM: Australian scientists have turned ordinary cooking oil into graphene, in a discovery they say lowers its cost to produce. Graphene, a strong carbon material, is just one atom wide and conducts electricity better than copper. The new method involves heating soybean oil in ambient air until it breaks down into "carbon building units that are essential for the synthesis of graphene". It is then rapidly cooled on nickel foil into a thin rectangle. Now researchers say they can make graphene with soybean oil, potentially making it more commercially viable. Graphene is hoped to have numerous applications including in electronics, biomedical devices and water filtration.The new method involves heating soybean oil in ambient air until it breaks down into "carbon building units that are essential for the synthesis of graphene", the CSIRO said. It is then rapidly cooled on nickel foil into a thin rectangle. Dr Han said the process is simpler and safer than existing methods, which use explosive compressed gases and vacuum processing. He said under current technology, a high-quality graphene film with a 10cm (4 inches) diameter costs up to A$1000 (£600, $750). The new method could make it "significantly"
a. cheaper b.costly c. redundant d. expensive.

Q12. Nature 538, 359–363 (20 October 2016): Received 26 February 2016: Multi-petahertz electronic metrology: we demonstrate the extension of electronic metrology to the multi-petahertz (10¹⁵ hertz) frequency range. We use single-cycle intense optical fields (about one volt per ångström) to drive electron motion in the bulk of silicon dioxide, and then probe its dynamics by using attosecond (10⁻¹⁸ seconds) streaking to map the time structure of emerging isolated attosecond extreme ultraviolet transients and their optical driver. The data establish a firm link between the emission of the extreme ultraviolet radiation and the light-induced intraband, phase-coherent electric currents that extend in frequency up to about eight petahertz, and enable access to the dynamic nonlinear conductivity of silicon dioxide. Direct probing, confinement and control of the waveform of intraband currents inside solids on attosecond timescales establish a method of realizing multi-petahertz coherent electronics. We expect this technique to enable new ways of exploring the interplay between electron dynamics and the structure of condensed matter on the atomic scale. Manish Garg said they achieved electrons moving at a speed of frequency close to 1015 (one million billion) hertz. In future we run integrated chips by nanofilms of silicon dioxide that are transparent to laser and absorb less
a. frequency b. electrons c. heat d.light

Q13. RAPID BURSTER TYPE II MAGNETIC FIELD 05 December 2016: Scientists observing a curious neutron star in a binary system known as the 'Rapid Burster' may have solved a forty-year-old mystery surrounding its puzzling X-ray bursts. They discovered that its magnetic field creates a gap around the star, largely preventing it from feeding on matter from its stellar companion. Gas builds up until, under certain conditions, it hits the neutron star all at once, producing intense flashes of X-rays. The discovery was made with space telescopes including ESA's XMM-Newton. But the Rapid Burster is a peculiar source: at its brightest, it does emit these type-I flashes, while during periods of lower X-ray emission, it exhibits the much more elusive 'type-II' bursts – these are sudden, erratic and extremely intense releases of X-rays. Bursts of type-II liberate enormous amounts of energy during periods otherwise characterised by very little emission occurring. The observations indicate that there is a gap of roughly 90 km between the neutron star and the inner edge of the accretion disc. While not impressive on cosmic scales, the size of the gap is much larger than the neutron star itself, which has a radius of about 10 km. the strength of the neutron star's magnetic field: at 6 × 108 G, it is around a billion times stronger than Earth's and, most important, over five times stronger than observed in other neutron stars with a low-mass stellar companion. MNRAS (2016) 466 (1): L98-L102. 05 December 2016. The neutron star (NS) low-mass X-ray binary (LMXB) the Rapid Burster (RB; MXB 1730-335) uniquely shows both Type I and Type II X-ray bursts. The origin of the latter is ill-understood but has been linked to magnetospheric gating of the accretion flow. We present a spectral analysis of simultaneous Swift, NuSTAR and XMM–Newton observations of the RB during its 2015 outburst. Although a broad Fe K line has been observed before, the high quality of our observations allows us to model this line using relativistic reflection models for the first time. We find that the disc is strongly truncated at 41.8^+6.7_−5.3 gravitational radii (∼87 km), which supports magnetospheric Type II burst models and strongly disfavours models involving instabilities at the innermost stable circular orbit. Assuming that the Rapid Burster magnetic field indeed truncates the disc, we find B = (6.2 ± 1.5) × 10^8 G, larger than typically inferred for NS LMXBs. In addition, we find a low inclination (i=29⁰ ± 2⁰). Finally, we comment on the origin of the Comptonized and thermal components in the Rapid Burster

a. Type I b. type II c. magnetic field d. spectrum

Q14. Mauritius is only a few million years old, while some recently discovered zircon crystals on the island were estimated at 3 billion years old. “The fact that we have found zircons of this age proves that there are much older crustal materials under Mauritius that could only have originated from a continent. An ancient continent that was once sandwiched between India and Madagascar now lies scattered on the bottom of the Indian Ocean. The first clues to the continent’s existence came when some parts of the Indian Ocean were found to have stronger gravitational fields than others, indicating thicker crusts. One theory was that chunks of land had sunk and become attached to the ocean crust below. Mauritius was one place with a powerful gravitational pull. Although Mauritius is only 8 million years old, some zircon crystals on the island’s beaches are almost 2 billion years old. Volcanic eruptions may have ejected the zircon from ancient rock below. There is evidence that other volcanic islands in the Indian Ocean, including the Cargados Carajos, Laccadive and Chagos islands, also sit on fragments of Mauritia. Gondwana was a supercontinent that existed more than 200 million years ago and contained rocks as old as 3.6 billion years old, before it split up into what are now the continents of Africa, South America, Antarctica, India and Australia. We document the first U–Pb zircon ages recovered directly from 5.7 Ma Mauritian trachytic rocks. We identified concordant Archaean xenocrystic zircons ranging in age between 2.5 and 3.0 Ga within a trachyte plug that crosscuts Older Series plume-related basalts of Mauritius. Our results demonstrate the existence of ancient continental crust beneath Mauritius; based on the entire spectrum of U–Pb ages for old Mauritian zircons, we demonstrate that this ancient crust is of central-east Madagascar affinity, which is presently located ∼700 km west of Mauritius. This makes possible a detailed reconstruction of Mauritius and other Mauritian continental fragments, which once formed part of the ancient nucleus of Madagascar and southern India. Ashwal, L. D. et al. Archaean zircons in Miocene oceanic hotspot rocks establish ancient continental crust beneath Mauritius. Nat. Commun. 8, 14086, 2017. Thicker crusts indicate

a. Zircons b. Gravitational Fields c. Supercontinent d. Rocks of 3.5Ga

Q15. Dark Matter Candidates in a Visible Heavy QCD Axion Model: Hajime Fukuda, Masahiro Ibe and Tsutomu T. Yanagida,Kavli, Japan: (Dated: February 2, 2017): Abstract: In this paper, we discuss dark matter candidates in a visible heavy QCD axion model. There, a mirror copied sector of the Standard Model with mass scales larger than the Standard Model is introduced. By larger mass scales of the mirrored sector, the QCD axion is made heavy via the axial anomaly in the mirrored sector without spoiling the Peccei-Quinn mechanism to solve the strong CP-problem. Since the mirror copied sector possesses the same symmetry structure with the Standard Model sector, the model predicts multiple stable particles. As we will show, the mirrored charged pion and the mirrored electron can be viable candidates for dark matter. They serve as self-interacting dark matter with a long range force. We also show that the mirrored neutron can be lighter than the mirrored proton in a certain parameter region. There, the mirrored neutron can also be a viable dark matter candidate when its mass is around 100 TeV. It is also shown that the mirrored neutrino can also be a viable candidate for

a. QCD Axion b. CP-problem c. Axion Model d. dark matter

Q16. Topologically protected Dirac plasmons in graphene: Deng Pan, Rui Yu, Hongxing Xu and F. Javier García de Abajo, Barcelona, Spain, javier.garciadeabajo@icfo.es; Abstract: Topological optical states exhibit unique immunity to defects and the ability to propagate without losses rendering them ideal for photonic applications. A powerful class of such states is based on time-reversal symmetry breaking of the optical response. However, existing proposals either involve sophisticated and bulky structural designs or can only operate in the microwave regime. Here, we propose and provide a theoretical proof-of-principle demonstration for highly confined topologically protected optical states to be realized at infrared frequencies in a simple 2D material structure—a periodically patterned graphene monolayer—subject to a magnetic field below 1 tesla. In our graphene honeycomb superlattice structures plasmons exhibit substantial nonreciprocal behavior at the superlattice junctions, leading to the emergence of topologically protected edge states and localized bulk modes enabled by the strong magneto-optical response of this material, which leads to time-reversal symmetry breaking already at moderate static magnetic fields. The proposed approach is simple and robust for realizing topologically nontrivial 2D optical states, not only in graphene, but also in other 2D atomic layers, and could pave the way for realizing fast, nanoscale, defect-immune devices for integrated photonics
a. Theory b. Applications c. plasmons d. applications

Q17. Solitonic Excitations in Collisions of Superfluid Nuclei: Kazuyuki Sekizawa, Piotr Magierski, Gabriel Wlazłowski: Proceedings of the 26th International Nuclear Physics Conference (INPC2016), Adelaide, Australia, Sep. 11-16, 2016: ABSTRACT: We investigate the role of the pairing field dynamics in low-energy heavy ion reactions within the nuclear time-dependent density functional theory extended to superfluid systems. Recently, we have reported on unexpectedly large effects associated with the relative phase of the pairing field of colliding nuclei on the reaction outcomes, such as the total kinetic energy and the fusion cross section. [P. Magierski, K. Sekizawa, and G. Wlaz]. We have elucidated that the effects are due to creation of a "domain wall" or a "solitonic structure" of the pairing field in the neck region, which hinders energy dissipation as well as the neck formation, leading to significant changes of the reaction dynamics. The situation nicely mimics the one extensively studied experimentally with ultracold atomic gases, where two clouds of superfluid atoms possessing different phases of the pairing field are forced to merge, creating various topological excitations, quantum vortices and solitons, as well as Josephson currents. In this paper, we present unpublished results for a lighter system, namely, ⁴⁴Ca+ ⁴⁴Ca. It is shown that the pairing effects on the fusion hindrance are rather small in lighter systems, due to a strong tendency towards
a. Fission b. Fusion c. Collision d. reaction.

Q18. Entangling two atoms of different isotopes via Rydberg blockade: Y. Zeng, P. Xu, X.D. He, Y.Y. Liu, M. Liu, J. Wang, D.J. Papoular, G.V. Shlyapnikov, M.S. Zhan: ABSTRACT: Quantum entanglement is crucial for simulating and understanding exotic physics of strongly correlated many-body systems, such as high--temperature superconductors, or fractional quantum Hall states. The entanglement of non-identical particles exhibits richer physics of strong many-body correlations and offers more opportunities for quantum computation, especially with neutral atoms where in contrast to ions the interparticle interaction is widely tunable by Feshbach resonances. Moreover, the inter-species entanglement forms a basis for the properties of various compound systems, ranging from Bose-Bose mixtures to photosynthetic light-harvesting complexes. So far, the inter-species entanglement has only been obtained for trapped ions. Here we report on the experimental realization of entanglement of two neutral atoms of different isotopes. A ⁸⁷Rb atom and a ⁸⁵Rb atom are confined in two single--atom optical traps separated by 3.8 μm. Creating a strong Rydberg blockade, we demonstrate a heteronuclear controlled--NOT (C--NOT) quantum gate and generate a heteronuclear entangled state, with raw fidelities 0.73±0.01 and 0.59±0.03, respectively. Our work, together with the technologies of single--qubit gate and C--NOT gate developed for identical atoms, can be used for simulating any many--body system with multi-species interactions. It also has applications in quantum computing and quantum metrology, since heteronuclear systems exhibit advantages in low crosstalk and in memory
a. protection b. crosstalk c.simulation d. trap

Q19.Near-perfect broadband absorption from hyperbolic metamaterial nanoparticles: Conor T. Riley, Joseph S. T. Smalley, Jeffrey R. J. Brodie, Yeshaiahu Fainman , Donald J. Sirbuly and Zhaowei Liu Mikhail A. Kats, University of Wisconsin, Madison, WI, and accepted by Evelyn L. Hu;- August 9, 2016 & December 22, 2016: Significance: The ability to perfectly absorb light with optically thin materials poses a significant challenge for many applications such as camouflage, light detection, and energy harvesting. Current designs require planar reflectors that crack and delaminate after heating or flexing. Moreover, they cannot be transferred to more desirable substrates for mechanically flexible and low-cost applications. Although particulate-based materials overcome these challenges, broadband absorption from standalone systems has not been demonstrated. Here, a class of materials, transferrable hyperbolic metamaterial particles (THMMP), is introduced. When closely packed, these materials show broadband, selective, omni-directional, perfect absorption. This is demonstrated with nanotubes made on a silicon substrate that exhibit near-perfect absorption at telecommunication wavelengths even after being transferred to a mechanically flexible, visibly transparent polymer. Abstract: Broadband absorbers are essential components of many light detection, energy harvesting, and camouflage schemes. Current designs are either bulky or use planar films that cause problems in cracking and delamination during flexing or heating. In addition, transferring planar materials to flexible, thin, or low-cost substrates poses a significant challenge. On the other hand, particle-based materials are highly flexible and can be transferred and assembled onto a more desirable substrate but have not shown high performance as an absorber in a standalone system. Here, we introduce a class of particle absorbers called transferable hyperbolic metamaterial particles (THMMP) that display selective, omnidirectional, tunable, broadband absorption when closely packed. This is demonstrated with vertically aligned hyperbolic nanotube (HNT) arrays composed of alternating layers of aluminium-doped zinc oxide and zinc oxide. The broadband absorption measures >87% from 1,200 nm to over 2,200 nm with a maximum absorption of 98.1% at 1,550 nm and remains large for high angles. Furthermore, we show the advantages of particle-based absorbers by transferring the HNTs to a polymer substrate that shows excellent mechanical flexibility and visible transparency while maintaining near-perfect absorption in the telecommunications region. In addition, other material systems and geometries are proposed for a wider range of applications. zhaowei@ucsd.edu. or dsirbuly@ucsd.edu. At Infra Red it yields properties

a. remarkable b. astounding c.plasmonic d. vibrant

Q20. February 7, 2017 1:27 WSPC/INSTRUCTION FILE KEPLER: International Journal of Modern Physics: Conference Series c: The Authors: White Dwarf Stars: S. O. Kepler, Alejandra Daniela Romero, Ingrid Pelisoli & Gustavo Ourique: Brazil kepler@if.ufrgs.br: Received 3 Feb 2017: White dwarf stars are the ﬁnal stage of most stars, born single or in multiple systems. We discuss the identiﬁcation, magnetic ﬁelds, and mass distribution for white dwarfs detected from spectra obtained by the Sloan Digital Sky Survey up to Data Release 13 in 2016, which lead to the increase in the number of spectroscopically identiﬁed white dwarf stars from 5000 to 39000. This number includes only white dwarf stars with logg ≥ 6.5 stars, i.e., excluding the Extremely Low Mass white dwarfs, which are necessarily the by-product of stellar interaction. Axions and Dark Mass Axions are the best candidates for dark mass. White dwarf pulsations and luminosity function are consistent with extra cooling caused by axions of masses around

a. 17 ± 4 mev. b. 18 ± 4 mev c. 20 ± 4 mev d. 21 ± 4 mev

Q21. Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 7 February 2017: The Kinetically Dominated Quasar 3C 418: Brian Punsly and Preeti Kharb, USA 90274 and Italy, National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Post Bag 3, Ganeshkhind, Pune 411007, India E-mail: brian.punsly@cox.net: 7 February 2017: ABSTRACT The existence of quasars that are kinetically dominated, where the jet kinetic luminosity, Q, is larger than the total (IR to X-ray) thermal luminosity of the accretion ﬂow, Lbol, provides a strong constraint on the fundamental physics of relativistic jet formation. Since quasars have high values of Lbol by deﬁnition, only ∼ 10 kinetically dominated quasars (with Q/Lbol > 1) have been found, where Q is the long term time averaged jet power. We use low frequency (151 MHz−1.66 GHz) observations of the quasar 3C418 to determine Q ≈ 5.5 ± 1.3 × 1046ergs s−1. Analysis of the rest frame ultraviolet spectrum indicates that this equates to 0.57 ± 0.28 times the Eddington luminosity of the central supermassive black hole and Q/Lbol ≈ 4.8 ± 3.1, making 3C418 one of the most kinetically dominated quasars found to date. It is shown that this maximal Q/Lbol is consistent with models of magnetically arrested accretion of jet production in which the jet production reproduces the observed trend of a decrement in the extreme ultraviolet continuum as the jet power increases. This maximal condition corresponds to an almost complete saturation of the inner accretion ﬂow with vertical large scale magnetic ﬂux (maximum saturation). Kinetically Dominated Quasar 3C 418 one of the observed

a.9 b.10 c. 12 d. 13

Q22. Band Structure, Band Offsets, Substitutional Doping, and Schottky Barriers in InSe: Yuzheng Guo, John Robertson, UK : yuzheng.guo@swansea.ac.uk: Abstract. We present a comprehensive study of the electronic structure of the layered semiconductor InSe using density functional theory. We calculate the band structure of the monolayer and bulk material with the band gap corrected using hybrid functionals. The band gap of the monolayer is 2.4 eV. The band edge states are surprising isotropic. The electron affinities and band offsets are then calculated for heterostructures as would be used in tunnel field effect transistors (TFETs). The ionization potential of InSe is quite large, similar to that of HfSe₂ or SnSe₂, and so InSe is suitable to act as the drain in the TFET. The intrinsic defects are then calculated. For Se-rich layers, the Se adatom is the lowest energy defect, whereas for In-rich layers, the In adatom is most stable for Fermi energies across most of the gap. Both substitutional donors and acceptors are calculated to be shallow, and not reconstructed. Finally, the Schottky barriers of metals are found to be strongly pinned, with the Fermi level pinned by metal induced gap states about 0.5 eV above the valence band. We have carried out a comprehensive calculation of the electronic structure of monolayer InSe, including its band structure, bonding, optical gaps, band offsets against other 2D layered semiconductors, its native defects, its substitution dopants, and its contact properties. In many ways, monolayer InSe maintains the advantages of three-dimensional (3D) bonded semiconductors with low effective mass band edge states, and shallow dopant sites, while also possessing many advantages of 2D semiconductors such as the ability to form heterostructures of different band gaps, without being subject to the constraints of lattice matching that would hold in normal 3D semiconductors. Thus, it is very suitable for electronic devices such a tunnel FETs.

a. drain b. defect c. functional d. edge.

Q23. Quantum spin liquid with 7 elementary particles: Haoyu Wang, Hitesh J. Changlani, Yuan Wan, and Oleg Tchernyshyov: USA & Canada: We present an exactly solvable model of a quantum spin liquid with Abelian anyons in d = 2 spatial dimensions. With spins 1/2 on a triangular lattice and six-body interactions, our model has zero spin correlation length and localized elementary excitations like the toric codes of Kitaev and Wen. In contrast to those earlier models, it has more elementary particles—4 bosons and 3 fermions—and higher topological degeneracy of 64 on a torus. Elementary excitations are boson fermion pairs that come in 12 distinct ﬂavors. We use string operators to expose the topological nature of the model. DISCUSSION: We have presented an exactly solvable model of a quantum spin liquid on a triangular lattice with six-spin interactions. Strong quantum ﬂuctuations generate long-range entanglement of spins and topological order. Elementary excitations are nonlocal objects. To understand their nature, we have constructed natural building blocks of the model—string operators’ deﬁned on links of either the original or dual lattice. The geometry of our model gives rise to a larger variety of strings than in predecessor square-lattice models of Kitaev and Wen. Both of those had 2 bosonic strings and 1 fermionic, whereas ours has 4 bosonic and 3 fermionic string types. In all of these models, ends of strings are associated with elementary particles (hence the designation of strings as bosonic or fermionic). Particles of two distinct types are mutual semions, a feature also found in the Kitaev and Wen models. Elementary excitations in our model (deﬁned as smallest quanta of energy) are distinct from elementary particles (ends of strings). A single excitation can be viewed as a pair of elementary particles, one boson and one fermion. We thus have a large number, 4×3 = 12, distinct types of elementary excitations living on 12 sublattices. These elementary excitations are static in the exactly solvable model. A small modiﬁcation of the Hamiltonian will make them mobile. For weak perturbations away from the solvable point, these excitations will only be able to tunnel between sites of their own sublattice separated distance √12 apart. The large number of string types (and of elementary particles) directly translates into high topological degeneracy, 2⁶ on a torus. This number, and the Abelian nature of the anyons, suggests that our model is equivalent to three decoupled Z₂ gauge ﬁelds, each of which contributes a factor of 2². This could be veriﬁed by constructing three pairs of Z₂ electric charges and ﬂuxes {e_i , m_i}, i = 1,2,3, where the bosonic electric charge e i and magnetic ﬂux m i within any pair would be mutual semions and would have trivial braiding statistics with the members of the other pairs. Although this construction is indeed possible, it requires the use of composite particles as there are only 4 elementary bosons. E.g., {e₁, m₁} = {C, M}, {e₂, m₂} = {RY, RK}, {e₃, m₃} = {BCM,GCM}. Such an asymmetric construction does not look natural and provides no additional insights. If anything, it obscures the link between lattice symmetries and topological order. It would be interesting to see whether one may ﬁnd a model with less contorted interactions than the sixspin term. Our attempts to ﬁnd a Hamiltonian with two-spin interactions ´a la Kitaev’s honeycomb model with similar properties have so far been

a. unsuccessful b. successful c. dubious d. undetermined

Q24. Static structure of chameleon dark Matter as an explanation of dwarf spheroidal galactic core: Prolay Krishna Chanda, Subinoy Das∗ Indian Institute of Astrophysics, Bangalore, 560034, India: ABSTRACT: We propose a novel mechanism which explains cored dark matter density proﬁle in recently observed dark matter rich dwarf spheroidal galaxies. In our scenario, dark matter particle mass decreases gradually as function of distance towards the centre of a dwarf galaxy due to its interaction with a chameleon scalar. At closer distance towards galactic centre the strength of attractive scalar ﬁfth force becomes much stronger than gravity and is balanced by the Fermi pressure of dark matter cloud, thus an equilibrium static conﬁguration of dark matter halo is obtained. Like the case of soliton star or fermion Q-star, the stability of the dark matter halo is obtained as the scalar achieves a static proﬁle and reaches an asymptotic value away from the galactic centre. For simple scalar dark matter interaction and quadratic scalar self-interaction potential, we show that dark matter behaves exactly like cold dark matter (CDM) beyond few kpc away from galactic centre but at closer distance it becomes lighter and fermi pressure cannot be ignored anymore. Using Thomas-Fermi approximation, we numerically solve the radial static proﬁle of the scalar ﬁeld, fermion mass and dark matter energy density as a function of distance. We ﬁnd that for ﬁfth force mediated by an ultralight scalar, it is possible to obtain a ﬂattened dark matter density proﬁle towards galactic centre. In our scenario, the ﬁfth force can be neglected at distance r ≥ 1kpc from galactic centre and dark matter can be simply treated as heavy non-relativistic particles beyond this distance, thus reproducing the success of CDM at large scales. Though CDM cosmology is amazingly successful for its prediction in large scale observations like CMB, BAO, LSS but small scale galactic observations are incompatible for many CDM predictions. Core vs cusp problem in dwarf galaxies, is one such issue which remains as one of the strongest challenge to CDM paradigm. This small dwarf galaxies are dark matter rich, so even the baryonic feedback (which rescues other small scale CDM N-body issues) would not do a great job due to lack of baryons in dwarf galaxies. Recently, a solitonic cored proﬁle of ultralight scalar dark matter is proposed as a physical explanation of cored DM proﬁle. But within CDM, there exists no solid physical explanation for a cored proﬁle of dark matter towards the centre of these dSph galaxies. Here, for the ﬁrst time, we provide a possible physical explanation for CDM to form a cored density proﬁle through small scale modiﬁcation of gravity in presence of scalar ﬁfth force in dark matter sector. Due to variation of scalar ﬁeld proﬁle towards the centre of dSph, dark matter mass becomes lighter and fermi pressure starts to balance the ﬁfth force, giving a static conﬁguration of dark matter cloud. As the scalar ﬁeld value ﬂatten towards the centre, the dark matter density, which is a function of scalar ﬁeld proﬁle, tend to ﬂatten towards the centre, naturally giving a cored proﬁle. Also, it is instructive to note that the scalar ﬁeld value asymptotically drops to zero near ≃few kpc. As the dark matter mass is scalar ﬁeld (φ) dependent and inversely proportional to φ(r), naturally we see that dark matter behaves like CDM far away from the centre of

a. solitonic core b. fifth force c. dark matter d. galaxy

Q25. 2 Feb 2017: Quantum gauge symmetry of reducible gauge theory: Manoj Kumar Dwivedi∗ Department of Physics, Banaras Hindu University, Varanasi-221005, India. ABSTRACT: We derive the gaugeon formalism of the Kalb-Ramond ﬁeld theory, a reducible gauge theory, which discusses the quantum gauge freedom. In gaugeon formalism, theory admits quantum gauge symmetry which leaves the action form-invariant. The BRST symmetric gaugeon formalism is also studied which introduces the gaugeon ghost ﬁelds and gaugeon ghosts of ghosts ﬁelds. To replace the Yokoyama subsidiary conditions by a single Kugo-Ojima type condition the virtue of BRST symmetry is utilized. Under generalized BRST transformations, we show that the gaugeon ﬁelds appear naturally in the reducible gauge theory. Starting from the most general gauge-ﬁxing Lagrangian including the gaugeon ﬁelds, we have presented a general form of the BRST symmetric gaugeon formalism for the 2-form (reducible) gauge theory. This most general gauge-ﬁxing Lagrangian possesses the quantum gauge symmetry under which the Lagrangian remains form invariant. The theory contains two gauge parameters in which one gets shifted by the quantum gauge transformation. We have found that the gaugeon action follows two subsidiary conditions. By introducing Faddeev-Popov ghosts and ghosts of ghosts corresponding to the gaugeon ﬁelds, we have constructed a BRST symmetric gaugeon formalism for Abelian 2-form gauge theory. The BRST symmetry enables us to improve the Yokoyama’s subsidiary conditions by replacing them to a single Kugo-Ojima type subsidiary condition which is more acceptable. The quantum gauge transformation commutes with the BRST transformation. As a result, the BRST charge is invariant, and thus the physical subspace is also gauge invariant. We have generalized the BRST symmetry of the gaugeon action by making transformation parameter ﬁnite and ﬁeld dependent which still leaves action invariant. But, the functional measure is not invariant under such FFBRST transformations and leads to nontrivial Jacobian. Finally, we have shown that gaugeon ﬁelds can be introduced naturally in reducible gauge theory using FFBRST transformation. Although the present paper deals with the Abelian 2-form gauge theory only, these results are more general and will be valid for all gauge theories that are

a. symmetric b. reducible c. irreducible d. gaugeon ghosts

Q26. Feb, 8 2017 at 11:56 AM: AR Sco, resides in the constellation Scorpius, contains a rapidly spinning, burnt-out stellar remnant called a white dwarf, which lashes its neighbour, a red dwarf, with powerful beams of electrical particles and radiation, causing the entire system to brighten and fade dramatically twice every two minutes. The latest research establishes that the lash of energy from AR Sco is a focused ‘beam’, emitting concentrated radiation in a single direction, much like a particle accelerator, something which is totally unique in the known universe. AR Sco lies in the constellation Scorpius, 380 light-years from Earth, a close neighbour in astronomical terms. The white dwarf in AR Sco is the size of Earth but 200,000 times more massive, and is in a 3.6 hour orbit with a cool star one third the mass of the Sun. With an electromagnetic field 100 million times more powerful than Earth, and spinning on a period just shy of two minutes, AR Sco produces lighthouse-like beams of radiation and particles, which lash across the face of the cool star, a red dwarf. As the researchers previously discovered, this powerful light house effect accelerates electrons in the atmosphere of the red dwarf to close to the speed of light, an effect never observed before in similar types of binary stars. The red dwarf is thus powered by the kinetic energy of its spinning neighbour. The distance between the two stars is around 1.4 million kilometres, which is three times the distance between the Moon and the Earth. Polarimetric evidence of a white dwarf pulsar in the binary system AR Scorpii: D.A.H. Buckley, et al., Nature Astronomy 1, Number 0029, 2017: Received: 22 September 2016 Accepted: 07 December 2016 Published online: 23 January 2017:The variable star AR Scorpii (AR Sco) was recently discovered to pulse in brightness every 1.97 min from ultraviolet wavelengths into the radio regime. The morphology of the modulated linear polarization is similar to that seen in the Crab pulsar, albeit with a more complex waveform owing to the presence of two periodic signals of similar frequency. Magnetic interactions between the two component stars, coupled with synchrotron radiation from the white dwarf, power the observed polarized and non-polarized emission. AR Sco is therefore the first example of a white dwarf pulsar. A fast-spinning (spin period P_s = 117.1 s) white dwarf, showing strong brightness variations across most of the electromagnetic spectrum (ultraviolet to radio), most strongly modulated on the P_b = 118.2-s beat (synodic) period, and its harmonics. The spin-down of the white dwarf (Ṗb=3.92×10⁻¹³ ss⁻¹) powers non-thermal emission, whose luminosity far exceeds (by a factor of ≥14)the combined luminosity of the stellar components and dominates the spectral energy distribution (SED). These observations were explained in terms of beamed synchrotron radiation from the white dwarf, some of which is reprocessed by the companion star. The weak X-ray emission suggests that little accretion power is produced in AR Sco, which either implies that it is currently in a propeller mass ejection phase or there is no mass transfer at all. If the former, then it would be similar to the white dwarf in the cataclysmic variable AE Aquarii, which has a 33-s spin period and a Ṗ =5.6×10⁻¹⁴ss⁻¹. However, the lack of flickering and broad emission lines in AR Sco, indicative of mass outflows which are seen in AE Aqr, implies no mass loss and suggests that a different mechanism is draining the rotational kinetic energy from the rapidly rotating white dwarf in AR Sco, perhaps similar to that operating in pulsars, namely dipole radiationand magneto-hydrodynamic (MHD)

a. collisions b. pulses c. emissions d. interactions

Q27. [gr-qc] Feb 9, 2017: Gravitational Coupling from Active Gravity: Tao Lei, Zi-Wei Chen, Zhen-Lai Wang, and Xiang-Song Chen: Wuhan 430074, China:(Dated: February 10, 2017): Abstract: We attempt to construct a gravitational coupling by pre-selecting an energy-momentum tensor as the source for gravitational ﬁeld. The energy-momentum tensor we take is a recently derived new expression motivated by joint localization of energy and momentum in quantum measurement. This energy-momentum tensor diﬀers from the traditional canonical and symmetric ones, and the theory we obtain is of an Einstein-Cartan type, but derived from a minimal coupling of a Lagrangian with second-derivative, and leads to additional interaction between torsion and matter, including the scalar ﬁeld. For the scalar ﬁeld, the theory can also be derived in the Riemann space-time by a non-minimal coupling. Our study gives hint on more general tests of general relativistic eﬀects. As the Einstein-Cartan theory does, our model leads to spin contact interaction, but of more extensive structures. Certainly, the test of such contact interaction has to await extremely precise measurements, but it does not mean that our discussion is purely academic. In fact, the most valuable light which our study might shed on the test of gravitational eﬀect, independent of the possible merit of our gravitational-coupling model itself, is that if T ^µν g diﬀers from T ^µν _eﬀ, then some peculiar eﬀect may occur. For example, in Einstein’s general relativity, it is T ^µν g that couples to gravity, while during a quantum measurement the eﬀective ﬂuxes of energy and momentum of a quantum wave is dictated by T ^µν _eﬀ , which is indeed diﬀerent from T ^µν g. This may lead to some kind of non-local violation of universality of free fall for quantum waves, and one may conjecture a possible gravitational discrimination of freely falling atomic waves of diﬀerent species. In this paper, we have worked with massive vector ﬁeld to avoid the discussion of gauge invariance, which is highly tricky and controversial. In the Riemann-Cartan space-time, the minimal coupling between gauge ﬁeld and torsion is gauge-dependent and hence often abandoned. Nethertheless, the recent technique to construct gauge-invariant gluon spin, may be adopted to build a gauge-invariant minimal coupling of photon or gluon to torsion. Thus, exploring the interaction between torsion and gauge particles is of vital importance and interest for the fundamental aspects of not only gravity, but also gauge theory.

a. Theory b. Experiment c. condition d. variability

Q28. [gr-qc] 1 Jan 2017: Neutron interference in the Earth’s gravitational ﬁeld: Andrei Galiautdinov and Lewis H. Ryder, USA, United Kingdom (Dated: January 3, 2017) ABSTRACT: This work relates to the famous experiments, performed in 1975 and 1979 by Werner et al., measuring neutron interference and neutron Sagnac eﬀects in the earth’s gravitational ﬁeld. Employing the method of Stodolsky in its weak ﬁeld approximation, explicit expressions are derived for the two phase shifts, which turn out to be in agreement with the experiments and with the previously obtained expressions derived from semi-classical arguments: these expressions are simply modiﬁed by relativistic correction

a. limits b. factors c. rules d. gauge

Q29. WKB Approximation for a Deformed Schrodinger-like Equatio and its Applications to Quasi-normal Modes of Black Holes and Quantum Cosmology: Bochen Lv, Peng Wang, and Haitang Yang, China, Abstract: In this paper, we use the WKB approximation method to approximately solve a deformed Schrodinger-like diﬀerential equation: which are frequently dealt with in various eﬀective models of quantum gravity, whe re the parameter α characterizes eﬀects of quantum gravity. For an arbitrary function g (x) satisfying several properties proposed in the paper, we ﬁnd the WKB solutions, the WKB connection formulas through a turning point, the deformed Bohr–Sommerfeld quantization rule, and the deformed tunnelling rate formula through a potential barrier. Several examples of applying the WKB approximation to the deformed quantum mechanics are investigated. In particular, we calculate the bound states of the Po¨schl-Teller potential and estimate the eﬀects of quantum gravity on the quasi-normal modes of a Schwarzschild black hole. Moreover, the area quantum of the black hole is considered via Bohr’s correspondence principle. Finally, the WKB solutions of the deformed Wheeler–DeWitt equation for a closed Friedmann universe with a scalar ﬁeld are obtained, and the eﬀects of quantum gravity on the probability of suﬃcient inﬂation is discussed in the context of the tunnelling proposal.

a. proposal b. effect c. Possibility d. conjecture

Q30. [hep-th] 9 Feb 2017: What is the Magnetic Weak Gravity Conjecture for Axions? Arthur Hebecker, Philipp Henkenjohann and Lukas T. Witkowski: Germany and France (UMR du CNRS 7164): Abstract: The electric Weak Gravity Conjecture demands that axions with large decay constant f couple to light instantons. The resulting large instantonic corrections pose problems for natural inﬂation. We explore an alternative argument based on the magnetic Weak Gravity Conjecture for axions, which we try to make more precise. Roughly speaking, it demands that the minimally charged string coupled to the dual 2-form-ﬁeld exists in the eﬀective theory. Most naively, such large-f strings curve space too much to exist as static solutions, thus ruling out large-f axions. More conservatively, one might allow non-static string solutions to play the role of the required charged objects. In this case, topological inﬂation would save the super planckian axion. Furthermore, a large-f axion may appear in the low-energy eﬀective theory based on two subplanckian axions in the UV. The resulting eﬀective string is a composite object built from several elementary strings and domain walls. It may or may not satisfy the magnetic Weak Gravity Conjecture depending on how strictly the latter is interpreted and on the cosmological dynamics of this composite object, which remain to be fully understood. Finally, we recall that large-ﬁeld brane inﬂation is naively possible in the codimension-one case. We show how string-theoretic back-reaction closes this apparent loophole of large-f (non-periodic)

a. pseudo-instantons b. pseudo-axion c. pseudo-rotons d. planckion-axion

Q31. [hep-th] 2 Jan 2017: Generalized Uncertainty Principle as a Consequence of the Eﬀective Field Theory: Mir Faizal, Ahmed Farag Ali, Ali Nassar, Canada, Egypt, Netherlands: Abstract: We will demonstrate that the generalized uncertainty principle exists because of the derivative expansion in the eﬀective ﬁeld theories. This is because in the framework of the eﬀective ﬁeld theories, the minimum measurable length scale has to be integrated away to obtain the low energy eﬀective action. We will analyse the deformation of a massive free scalar ﬁeld theory by the generalized uncertainty principle, and demonstrate that the minimum measurable length scale corresponds to a second more massive scale in the theory, which has been integrated away. We will also analyse CFT operators dual to this deformed scalar ﬁeld theory, and observe that scaling of the new CFT operators indicates that they are dual to this more massive scale in the theory. We will use holographic renormalization to explicitly calculate the renormalized boundary action with counter terms for this scalar ﬁeld theory deformed by generalized uncertainty principle, and show that the generalized uncertainty principle contributes to the matter conformal anomaly. It may be noted that we only analysed the higher derivative corrections for an ordinary scalar ﬁeld theory on AdS and related it to the conformal ﬁeld theory on its boundary. The precise correspondence between a ordinary scalar ﬁeld theory on AdS and a suitable conformal ﬁeld theory on its boundary is given by the Rehren duality. It would thus be interesting to analyse the boundary dual to the scalar ﬁeld theory on the bulk in the framework of algebraic holography. It may also be interesting to analyse the bulk action of various supergravity theories in the framework of eﬀective ﬁeld theories. We will expect that the bulk action will receive higher derivative corrections from purely stringy excitations. Then it will be possible to relate these higher derivative corrections for the bulk supergravity action to the super-conformal ﬁeld theories on the boundary. As the full string theory is dual to boundary super-conformal ﬁeld theory, we expect that the conformal dimension of marginal operators will not receive any correction from these purely stringy excitations. However, conformal dimensions of both the relevant and the irrelevant operators are expected to receive

a. trends b. duality c. corrections d. theories

Q32. International Journal of Photo-energy Volume 2012, Article ID 269654, 10 pages. Nitrogen Incorporation in TiO₂: Does It Make a Visible Light Photo-Active Material? B. Viswanathan and K. R. Krishanmurthy, National Centre for Catalysis Research, Indian Institute of Technology Madras, Chennai 600 036, India, bvnathan@iitm.ac.in, Received 18 January 2012; Revised 11 April 2012; Accepted 26 April 2012, ABSTRACT: The possibility of hydrogen production by photo-catalytic decomposition of water on titania has provided the incentive for intense research. Titania is the preferred semiconductor for this process, in spite of its large band gap (∼3.2eV) that restricts its utility only in the UV region. Various sensitization methodologies have been adopted to make titania to be active in the visible region. Doping of TiO₂ with nitrogen is one such method. The purpose of this presentation is to examine the state and location of nitrogen introduced in TiO₂ lattice and how far the shift of optical response to visible radiation can be beneﬁcial for the observed photo-catalysis. The speciﬁc aspects that are discussed in this article are: (i) N-doped titania surface adopts a non-native conﬁguration, though the bulk material is still in the native conﬁguration of pure TiO₂ (ii) Though the nitrogen doped materials showed optical response in the visible region, the changes/improvements in photo-catalytic activity are only marginal in most of the cases. (iii) The exact chemical nature/state of the introduced nitrogen, and its location in titania lattice, substitutional and/or interstitial, is still unclear (iv) Is there a limit to the incorporation of nitrogen in the lattice of TiO₂? Bare semiconductor absorbs UV radiation while the localized energy levels of nitrogen above valence band facilitate the visible light

a. emission b. oscillation c. scattering d. absorption.

Q33. Solar Energy Materials and Solar Cells: Vol. 151, 1 July 2016, Pages 36-43: High performance perovskite solar cells with functional highly porous TiO₂ thin films constructed in ambient air: Rapsomanikis, A, Karageorgopoulos, D, Lianos, P., Stathatos, E.,:Greece: Abstract: In the present work we report the synthesis of highly meso- and macro-porous thin TiO₂ films as efficient scaffolds for improved performance of heterojunction solid state perovskite solar cells made in F ambient air. TiO₂ films were prepared using sol-gel process and Pluronic P-123 block copolymer as organic template while they were formed on conductive glass substrates by spin-coating method. The films were employed to the construction of very efficient perovskite solar cells made at ambient conditions where CH₃NH₃PbI_3-xCl_x mixed halide perovskite was used as light harvester and P3HT polymer as hole conductor. The very rough and highly porous TiO₂ films proved to be an excellent host material for perovskite growth. The structural properties of the TiO₂ electron transport layer, thickness, particle size and porosity, strongly affected the overall conversion efficiency. The optimal structure and materials composition exhibited a notably high current density J_sc of 23.8 mA/cm², V_oc of 0.995 V and fill factor of 0.58. These solar cells prepared under ambient conditions yielded an average power conversion efficiency of 13.7% among the best ever recorded with P3HT polymer as hole conducting

a. material b. conductor c. structure d. polymer

Q34. Spin excitations and the Fermi surface of superconducting FeS: Haoran Man et al. ABSTRACT: High-temperature superconductivity occurs near antiferromagnetic instabilities and nematic state. Debate remains on the origin of nematic order in FeSe and its relation with superconductivity. Here, we use transport, neutron scattering and Fermi surface measurements to demonstrate that hydro-thermo grown superconducting FeS, an isostructure of FeSe, is a tetragonal paramagnet without nematic order and with a quasiparticle mass signiﬁcantly reduced from that of FeSe. Only stripe-type spin excitation is observed up to 100 meV. No direct coupling between spin excitation and superconductivity in FeS is found, suggesting that FeS is less correlated and the nematic order in FeSe is due to competing checkerboard and stripe spin ﬂuctuations. We use transport, neutron scattering and Fermi surface measurements to demonstrate that superconducting FeS, an isostructure of FeSe, is a tetragonal paramagnet without nematic order and with a quasiparticle mass signiﬁcantly reduced from that of FeSe. Our neutron scattering experiments in the energy regime below 100 meV reveal only stripe-type spin ﬂuctuations in FeS that are not directly coupled to superconductivity. These properties suggest that FeS is a weakly correlated analog of FeSe and, moreover, that the nematic order in FeSe is due to the frustrated magnetic interactions underlying the competing checkerboard and stripe spin

a. densities b. Excitations c. fluctuations d. interactions

Q35. Majorana qubits in topological insulator nanoribbon architecture: J. Manousakis et al, Germany (Dated: February 10, 2017). ABSTRACT: We describe designs for the realization of topological Majorana qubits in terms of proximitized topological insulator nanoribbons pierced by a uniform axial magnetic ﬁeld. This platform holds promise for particularly robust Majorana bound states, with easily manipulable inter-state couplings. We propose proof-of-principle experiments for initializing, manipulating, and reading out Majorana box qubits deﬁned in ﬂoating devices dominated by charging eﬀects. We argue that the platform oﬀers design advantages which make it particularly suitable for extension to qubit network structures realizing a Majorana surface code. In this paper, we have outlined how Majorana qubits can be deﬁned and operated in aproximitized TI nanoribbon architecture. The key element of the construction are gate-tunable internal tunnel junctions realized through narrowed regions of lowered axial magnetic ﬂux in TI nanoribbons. This allows us to tune the hybridization of MBSs emerging from a topologically protected helical 1D surface state mode, and thereby makes it possible to manipulate the quantum information. The linear dispersion of the 1D modes in this platform is expected to give the MBSs a high level of

a. dispersion b. robustness c. hybridization d. insulation.

Q36. Solar Energy Materials and Solar Cells: Volume 164, May 2017, Pages 47–55: Low-temperature electrodeposited crystalline SnO₂ as an efficient electron-transporting layer for conventional perovskite solar cells: Jung-Yao Chen et al., 1. A highly crystalline SnO2 has been fabricated through a low-temperature (below 100^OC) electrodeposition technique. 2. The SnO₂ film serving as electron-transporting layer facilitate the fabrication of n-i-p planar perovskite solar cell. 3. An efficient (PCE: 13.88%) perovskite solar cell with negligible hysteresis was demonstrated. Abstract: Tin oxide (SnO₂) has recently attracted significant research interest for its role functioning as an efficient electron-transporting layer (ETL) due to its higher charge mobility than the commonly used titanium oxide (TiO₂) for realizing high-performance perovskite solar cells (PVSCs). However, it is still challenging to develop a facile, low-temperature solution-based (<100^oC) processing method to synthesize crystalline SnO₂with desirable charge mobility, which can facilitate its widespread applications in flexible optoelectronic devices. In this work, we utilize an electrochemical deposition technique to prepare SnO₂ films at a reduced temperature below 100^oC. The electrodeposition endows the SnO₂ film with high crystallinity and conductivity in addition to high transparency across the visible spectrum. Efficient photoluminescence (PL) quenching is observed in the bi-layered SnO₂/CH₃NH₃PbI₃ film, manifesting its efficient electron extraction capability from perovskite. Consequently, a conventional n-i-p PVSC using this electrodeposited SnO₂ ETL shows a high PCE of 13.88% with negligible hysteresis. This work demonstrates a low-temperature solution-based preparation route for making crystalline SnO₂ and its potential for application in large-scale PVSC

a. production b. fabrication c. design d. research

Q37. Meta-lenses bring benchtop performance to small, hand-held spectrometer: February 9, 2017: A research team of physicists from Harvard University has developed new hand-held spectrometers capable of the same performance as large, benchtop instruments. The researchers' innovation explained this week in APL Photonics, derives from their ground breaking work in meta-lenses. The hand-held spectrometers offer real promise for applications ranging from health care diagnostics to environmental and food monitoring. To maintain performance while reducing spectrometer size, this team of researchers has developed a spectrometer incorporating meta-lenses that combine the functionalities of a traditional grating and focusing mirror into a single component, as well as having much greater ability to spatially separate wavelengths (the so-called dispersion). In all, the overall size of the spectrometer is significantly reduced without sacrificing performance. Zhuetal, APL Photonics2, 036103 (2017). In summary, we have demonstrated an ultra-compact meta-spectrometer based on integrating multiple planar off-axis meta-lenses at visible wavelengths. This has several advantages over its traditional grating based counterparts: ﬁrst, it combines the functions of a focusing and dispersive element in a single planar structure, which eliminates the need for rotating turrets or focusing mirrors. Second, in terms of performance, it surpasses conventional blazed grating elements as one can achieve extremely large dispersions which are otherwise unattainable. In addition, the integration of several meta-lenses with different NAs on one substrate allows for multiple different spectral resolutions and a ﬂexible working wavelength range with no further increase in system bulk or complexity. Finally, the meta-lenses can provide extra information about the circular polarization state of incident light, which is not attainable for conventional devices without the use of additional optical elements (e.g., polarizer and wave plates). The use of dielectric TiO2 as the working material also renders it compatible with existing CMOS processes where large scale production could take place in a single lithographic step or be monolithically integrated with sensor technologies. We envision numerous potential applications in health care, environmental sensing, and related areas for this

a. methodology b. technology c. integration d. dispersion

Q38. COLOURFUL FLASHES ABOVE THE CLOUDS ON INDIA:

Fig: India Upper atmosphere with

a variety of elves streaks.

08/02/2017: In Earth’s upper atmosphere, blue jets, red sprites, pixies, halos, trolls and elves streak toward space, rarely caught in the act by human eyes. This mixed-bag of quasi-mythological terms are all names for transient luminous events, or, quite simply, forms of lightning that dance atop thunderstorm clouds. Airplane pilots have reported seeing them, but their elusive nature makes them hard to study. But ESA astronaut Andreas Morgensen, while aboard the International Space Station in September 2015, filmed hundreds of blue jets flashing over a thunderstorm that was pounding the Bay of Bengal, confirming a mysterious atmospheric phenomenon. According to Morgensen and researchers at the Denmark National Space Institute, these observations are the first of their kind, and offer a rare glimpse of poorly understood atmospheric phenomena. His work, which was published in the journal Geophysical Research Letters, also proves that the ISS is a perfect lab for studying elves and pixies, and a planned follow-up mission should reveal even more. On Sept. 8, he filmed a doozy near India, and recorded 245 blue flashes above the clouds in a 160-second video. The flashes were about 1 km wide, and 18 km in altitude. It isn’t clear what causes these blue flashes; scientists, in fact, aren’t sure how familiar cloud-to-ground lightning forms, either. These electrical charges from thunderstorms may alter chemistry in the upper atmosphere, which could have implications for Earth’s radiation balance. For example, the interaction between nitrogen and electricity is thought to give red sprites their colour.

a. Splendour b. rigour c. Splash d. colour

Q39. January 23, 2017: Forschungsverbund Berlin e.V. (FVB): Summary: For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequisite for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications. Today's quantum optical sensor is as small as a freezer and remains fully operational even after experiencing huge mechanical and thermal stress caused by the rocket launch. This ground breaking mission is a pathfinder for applications of quantum sensors in space. In the future, scientists expect to use quantum sensor technology to cope with one of the biggest challenges of modern physics: the unification of gravitation with the other fundamental interactions (strong, weak, and electro-magnetic force) in a single consistent theory. For this mission, the FBH has developed hybrid micro-integrated semiconductor laser modules that are suitable for application in space. These laser modules, together with optical and spectroscopic units provided by third partners, have been integrated and qualified by HU to provide the laser subsystem of the scientific payload. The results of this mission coordinated by Leibniz Universitaet Hannover do not only prove that quantum optical experiments with ultra-cold atoms are possible in space, but also give FBH and HU the opportunity to test their miniaturized laser system technology under real operating conditions. The results will also be used to prepare future missions which are already scheduled for launch. MAIUS, however, is not the first sounding rocket test for both institutions' laser technology in space. MAIUS constitutes a historical milestone for future missions in space that will take advantage of the full potential of quantum technology. For the first time world-wide, a Bose-Einstein condensate (BEC) based on rubidium atoms has been created on board of a sounding rocket and has been used to investigate atom interferometry in space. Quantum optical sensors based on BECs enable high-precision measurements of accelerations and rotations using laser pulses which provide a reference for precise determination of the positions of the atomic

a. cloud b. vision c. sounding d. experiments

Q40. Six-fold improved single particle measurement of the magnetic moment of the antiproton: H.Nagahama et al, Nature Communications 8, No. 14084, 2017: Received: 22 June 2016: Accepted: 28 November 2016: Pub:18 January 2017: ABSTRACT: The magnetic moment of the antiproton has been measured with a six-fold improvement in accuracy. The BASE collaboration at CERN has reported the best measurement to date, with an experimental uncertainly of 0.8 parts per million. This improves upon the 2013 measurement by the CERN-based ATRAP collaboration, which had 4.4 parts-per-million uncertainty. Both experiments had aimed to shed light on an important mystery of antimatter: while antimatter appears identical to matter at a particle level, the universe as a whole contains little antimatter – which suggests it is different. By measuring properties such as magnetic moment, scientists can test the Standard Model and its matter–antimatter symmetry for chinks that could explain the disparity. The BASE experiment cools antiprotons from CERN's antiproton decelerator to about 1 K before trapping them in electromagnetic containers. The containers store the antiprotons for long periods of time and release them individually into further traps where measurements are made. However, while the latest measurements show impressive accuracy, the antiproton magnetic moment was found to be the exact opposite of the protons’, just as predicted by the Standard Model. The next step for BASE is to try a new trapping technique that should improve uncertainty by a factor of up to 800, which could reveal a glimpse of new physics. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value g_p/2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement g_p/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.

a. 30 b. 20 c. 50 d. 40

Q41. APL PHOTONICS 2, 036103 (2017) Ultra-compact visible chiral spectrometer with meta-lenses AlexanderY.Zhu,et al, Massachusetts 02138, USA, Waterloo, Ontario N2L 3G1, Canada (Received 4 November 2016; accepted 5 January 2017; published online 7 February 2017). ABSTRACT: Conventional compact spectrometers have a ﬁxed spectral resolution and cannot resolve the polarization properties of light without additional optical elements, while their larger counterparts are bulky and costly. Here, we demonstrate multiple offaxis meta-lenses in the visible integrated on a single planar substrate. They possess both focusing and strongly dispersive properties and are designed to provide different spectral resolutions as well as working wavelength ranges on the same chip. We realize a compact spectrometer using only these meta-lenses and a CMOS camera and achieve detector-limited spectral resolutions as small as 0.3 nm and a total working wavelength range exceeding 170 nm for a beam propagation length of only a few cm. In addition, this spectrometer has the capability to resolve different helicities of light in a single measurement. This chip-camera setup represents the most compact conﬁguration so far achieved for a spectrometer with similar performance and functionality, and its compatibility with large-scale fabrication processes makes it broadly applicable. In summary, we have demonstrated an ultra-compact meta-spectrometer based on integrating multiple planar off-axis meta-lenses at visible wavelengths. This has several advantages over its traditional grating based counterparts: ﬁrst, it combines the functions of a focusing and dispersive element in a single planar structure, which eliminates the need for rotating turrets or focusing mirrors. Second, in terms of performance, it surpasses conventional blazed grating elements as one can achieve extremely large dispersions which are otherwise unattainable. In addition, the integration of several meta-lenses with different NAs on one substrate allows for multiple different spectral resolutions and a ﬂexible working wavelength range with no further increase in system bulk or complexity. Finally, the meta-lenses can provide extra information about the circular polarization state of incident light, which is not attainable for conventional devices without the use of additional optical elements (e.g., polarizer and wave-plates). The use of dielectric TiO₂ as the working material also renders it compatible with existing CMOS processes where large scale production could take place in a single lithographic step or be monolithically integrated with sensor technologies. We envision numerous potential applications in health care, environmental sensing, and related areas for this

a. technology b. invention c. production d. sensing

Q42. PREFERENTIAL HEATING AND ACCELERATION OF HEAVY IONS IN IMPULSIVE SOLAR FLARES Rahul Kumar, et al., (Dated: February 8, 2017). [physics.space-ph] 2 Feb 2017: ABSTRACT: We simulate decaying turbulence in a homogeneous pair plasma using three dimensional electromagnetic particle-in-cell(PIC) method. A uniform background magnetic ﬁeld permeates the plasma such that the magnetic pressure is three times larger than the thermal pressure and the turbulence is generated by counter-propagating shear Alfven waves. The energy predominately cascades transverse to the background magnetic ﬁeld, rendering the turbulence anisotropic at smaller scales. We simultaneously move several ion species of varying charge to mass ratios in our simulation and show that the particles of smaller charge to mass ratios are heated and accelerated to non-thermal energies at a faster rate, in accordance with the enhancement of heavy ions and non-thermal tail in their energy spectrum observed in the impulsive solar ﬂares. We further show that the heavy ions are energized mostly in the direction perpendicular to the background magnetic ﬁeld with a rate consistent with our analytical estimate of the rate of heating due to cyclotron resonance with the Alfven waves of which a large fraction is due to obliquely propagating

a. disturbances b. waves c. Plasma d. Heavy ions

Q43.arXiv:1702.03214[physics.gen-ph]: Neutrino masses from a cobimaximal neutrino mixing matrix: Asan Damanik∗ Department of Physics Education, Sanata Dharma, University Kampus III USD, Paingan Maguwoharjo Sleman Yogyakarta, Indonesia: Abstract: Recently, we have a conﬁdence that neutrino has a tiny mass and mixing does exist among neutrino ﬂovors as one can see from experimental data that reported by many collaborations. Based on experimental data that ﬂavor mixing does exist in neutrino sector which imply that all three mixing angles are nonzero, we derive the neutrino mass matrix from a cobimaximal neutrino mixing matrix. We also evaluate the prediction of neutrino mass matrix with texture zero from a cobimaximal neutrino mixing matrix on neutrino masses and eﬀective Majorana mass. By using the advantages of experimental data, the obtained neutrino masses are m₁ = 0.028188 eV, m₂ = 0.029488 eV, and m₃ = 0.057676 eV, and the eﬀective Majorana mass is <m_ββ> = 0.09896 eV that can be tested in future neutrinoless double beta decay experiments. After we have known the neutrino masses, we then calculate the prediction of cobimaximal mixing on eﬀective Majorana mass because the eﬀective Majorana mass is a parameter of interest in neutrinoless double beta decay. The eﬀective Majorana mass <m_ββ> is a combination of neutrino mass eigenstates and the neutrino mixing matrix terms as follow We have use a cobimaximal neutrino mixing matrix to obtain a neutrino mass matrix. The obtained neutrino mass matrix is constrained by two texture zero i.e. Mν(1,1) = 0 and Mν(2,3) = Mν(3,2) = 0 and by using the advantages of the experimental data of squared mass diﬀerence, then we can obtain neutrino masses in normal hierarchy i.e. m₁ = 0.028188eV, m₂ = 0.029488eV, and m₃ = 0.057676eV. By using the central values of reported experimental mixing angle θ13 and θ23 and obtained neutrino masses, the eﬀective Majorana mass is <m_ββ> = 0.09896eV that can be tested in future neutrinoless double beta decay

a. rules b. factors c. experiments d. methods

Q44. On the solution of linearized (linear in S-matrix) Balitsky-Kovchegov equation: [hep-ph] 13 Feb 2017: Raktim Abir and Mariyah Siddiqah, Aligarh - 202002, UP, India. (Dated: February 14, 2017): ABSTRACT: We revisited solution of a linearized form of leading order Balitsky-Kovchegov equation (linear in S-matrix for dipole-nucleus scattering). Here we adopted dipole transverse width dependent cut-oﬀ in order to regulate the dipole integral. We also have taken care of all the higher order terms (higher order in the cutoﬀ) that have been reasonably neglected before. The solution reproduces both McLerran-Venugopalan type initial condition (Gaussian in scaling variable) and Levin-Tuchin solution (Gaussian in logarithm of scaling variable) in the appropriate limits. It also connects this two opposite limits smoothly with better accuracy for sets of rescaled rapidity when compared to numerical solutions of full leading order Balitsky-Kovchegov equation. In this work we have revisited solution of a linearized form of LO BK equation. Unlike the earlier studies here we have adopted transverse width dependent cut-oﬀ in order to regulate the dipole integral. We also taken care of all the higher order terms (higher order in cut-oﬀ) that have been reasonably neglected before. Later was important in order to make the calculation consistent when away from vanishing cut-oﬀ. By demanding that dipole integral vanishes in the limit of vanishing transverse separation of the dipole and deﬁning the inverse of saturation momentum being equal to transverse separation of the parent dipole when dipole amplitude is half we derived a general form of solution which reproduce both McLerran-Venugopalan initial conditions (Gaussian in τ) and Levin-Tuchin solution (Gaussian in lnτ), with τ being scaling variable, in their appropriate limits. This new solution involving dilogarithm function connects both this limits smoothly and better approximates the numerical estimation of full leading order BalitskyKovchegov equation particularly inside saturation region. This also implies that linearized LO BK equation contains dynamics of dipole nucleus interaction throughout a wide kinematic domain of saturation. It would be interestingly to see how this solution modiﬁes for the running couplings improved or next to leading order BK equations, how it preserves the inherent conformal symmetry of the kernel, or to what extent it receives corrections from quadratic nonlinear term (in S-matrix) present in the Balitsky-Kovchegov

a. equation b. formalism c. dilogarithm d. functions

Q45. Resonant Generation of an Electron Positron Pair by Two Photons to Excited Landau Levels: J. Exp. Theor. Phys. 121(5) 813 (2015); M. M. Diachenko, O. P. Novak, R. I. Kholodov, Ukraine: [hep-ph] 13 Feb 2017, ABSTRACT: We consider the resonant generation of an electron-positron pair by two polarized photons to arbitrarily low Landau levels. The resonance occurs when the energy of one photon exceeds the one-photon generation threshold, and the energy of the other photon is multiple to the spacing between the levels. The cross section of the process is determined taking into account the spins of particles. The order of magnitude of the cross section is the highest when the magnetic moments of the particles are oriented along the magnetic ﬁeld. In this study, we consider the eﬀect of the resonant production of an electron-positron pair by two polarized photons in a magnetic ﬁeld on the excited Landau levels taking into account the spins of the particles. We calculate the resonant cross section for arbitrary polarizations of particles in the case when the electron and the positron occupy arbitrary low Landau

a. states b. groups c. levels d. photons

Q46. arXiv:1702.03321v1 [astro-ph.SR] 10 Feb 2017: February 14, 2017 Preprint: HYDROGEN BALMER LINE BROADENING IN SOLAR AND STELLAR FLARES: Adam F. Kowalski, Boulder, CO 80303, USA. Joel C. Allred NASA, Han Uitenbroek, USA, Rachel A. Osten, Baltimore, MD 21218, USA, John P. Wisniewski, OK 73019, USA, Suzanne L. Hawley, WA 98195, USA. ABSTRACT: The broadening of the hydrogen lines during ﬂares is thought to result from increased charge (electron, proton) density in the ﬂare chromosphere. However, disagreements between theory and modelling prescriptions have precluded an accurate diagnostic of the degree of ionization and compression resulting from ﬂare heating in the chromosphere. To resolve this issue, we have incorporated the uniﬁed theory of electric pressure broadening of the hydrogen lines into the non-LTE radiative transfer code RH. This broadening prescription produces a much more realistic spectrum of the quiescent, A0 star Vega compared to the analytic approximations used as a damping parameter in the Voigt proﬁles. We test recent radiative-hydrodynamic (RHD) simulations of the atmospheric response to high non-thermal electron beam ﬂuxes with the new broadening prescription and ﬁnd that the Balmer lines are over broadened at the densest times in the simulations. Adding many simultaneously heated and cooling model loops as a “multithread” model improves the agreement with the observations. We revisit the three-component phenomenological ﬂare model of the YZ CMi Mega-ﬂare using recent and new RHD models. The evolution of the broadening, line ﬂux ratios, and continuum ﬂux ratios are well reproduced by a multithread model with high-ﬂux non-thermal electron beam heating, an extended decay phase model, and a “hot spot” atmosphere heated by an ultra-relativistic electron beam with reasonable ﬁlling factors: ∼ 0.1%, 1%, and 0.1% of the visible stellar hemisphere, respectively. The new modelling motivates future work to understand the origin of the extended gradual phase emission. In solar ﬂares, the broadening evolution on several second timescales in spatially resolved kernels can be constrained with future spectral observations with the Daniel K. Inouye Solar Telescope. As shown from the modelling of the YZ CMi Megaﬂare, spatially resolved spectra of the hydrogen lines and hydrogen edge wavelength regions during large solar events would place strong constraints on the variation of the charge density and heating mechanisms across ﬂare ribbons.

a. rhythms b. ribbons c. flaps d. spots.

Q47. [cond-mat.quant-gas]: 28 Jun 2016: Simulating generic spin-boson models with matrix product states: Michael L. Wall, Arghavan Safavi-Naini, and Ana Maria Rey JILA, NIST and University of Colorado, 440 UCB, Boulder, CO 80309, USA and Centre for Theory of Quantum Matter, University of Colorado, Boulder, Colorado 80309, USA (Dated: June 29, 2016): ABSTRACT: The global coupling of few-level quantum systems (“spins”) to a discrete set of bosonic modes is a key ingredient for many applications in quantum science, including large-scale entanglement generation, quantum simulation of the dynamics of long-range interacting spin models, and hybrid platforms for force and spin sensing. We present a general numerical framework for treating the out-of-equilibrium dynamics of such models based on matrix product states. Our approach applies for generic spin-boson systems: it treats any spatial and operator dependence of the two-body spin-boson coupling and places no restrictions on relative energy scales. We show that the full counting statistics of collective spin measurements and inﬁdelity of quantum simulation due to spin-boson entanglement, both of which are diﬃcult to obtain by other techniques, are readily calculable in our approach. We benchmark our method using a recently developed exact solution for a particular spin-boson coupling relevant to trapped ion quantum simulators. Finally, we show how decoherence can be incorporated within our framework using the method of quantum trajectories, and study the dynamics of an open-system spin-boson model with spatially non-uniform spin-boson coupling relevant for trapped atomic ion crystals in the presence of molecular ion impurities. Our approach is able to treat several competing interaction scales, as well as decoherence, on the same footing, and so provide a rigorous means for justifying eﬀective models of driven spin-boson systems in various parameter regimes. This is especially important for trapped ion quantum spin simulators in eﬀective transverse ﬁelds, where the presence of non-commuting interactions with comparable energy scales can fundamentally change the eﬀective spin physics in ways not captured by a perturbative approach. Additionally, while we focused on applications to trapped ion systems, our techniques can be applied to many other platforms, including quantum optics and optomechanics, and provide a scalable means for studying strongly correlated physics in these diverse systems. Our framework also applies to higher dimensional spin representations, such as spin-1, which can also be realized with trapped ion systems and can shed light on fundamental questions such as the nature of topological phases with long-range interactions. A generalization from discrete boson spectra to continuous boson spectra is possible, given a single global coupling operator between spins and bosons, using techniques based on orthogonal polynomials, while keeping well-deﬁned error. This can lead to new insights into quantum phases of correlated spins which are coupled to an external

a. forces b. phases c. bath d. decoherence

Q48. Generalized Dicke States: [quant-ph] 6 Sep 2016: S. Hartmann, Germany. (Dated: September 7, 2016): ABSTRACT: Quantum master equations are an important tool in quantum optics and quantum information theory. For systems comprising a small to medium number of atoms (or qubits), the non-truncated equations are usually solved numerically. In this paper, we present a group-theoretical super-operator method that helps solving these equations. To do so, we exploit the SU(4)-symmetry of the respective Lindblad operator and construct basis states that generalize the well-known Dicke states. This allows us to solve various problems analytically and to considerably reduce the complexity of problems that can only be solved numerically. Finally, we present three examples that illustrate the proposed method. We have presented a group-theoretical super-operator method to solve quantum master equations for a ﬁnite number of atoms (or quits). The method can be applied to many further problems in quantum optics and quantum information theory. Studies that used the method proposed in this paper include. Here are a few more examples. For quantum optical applications, it is interesting to couple the atoms to a radiation ﬁeld (using the Tavis-Cummings model) and to study, for example, the physics of few-atom lasers as well as phenomena such as resonance ﬂourescence and optical bistability in Z-atom systems in a cavity. The resulting equations have to be solved numerically, but the complexity of the problems will be considerably reduced with the help of the basis states proposed in this paper. On the more theoretical side and with an eye on applications in quantum information theory, it will be interesting to construct SU(4) coherent states and study their decoherence times. Moreover, one can ask which many-atom states are especially stable under the inﬂuence of decoherence, and which not? We believe that our method will be a valuable tool in these studies. While this paper focused on fully symmetrical states, states of mixed symmetry and fully antisymmetrical states can also be prepared experimentally (as admixtures to generalized Dicke states). In a sequel to this paper, we will develop the theory of these states and study some of its

a. applications b. resonances c. anti-symmetry d. features

Q49. A new infrared Fabry-P´erot-based radial-velocity-reference module for the SPIRou radial-velocity spectrograph. Cersullo Federica et al., Geneva Observatory, University of Geneva, Maillettes 51, CH-1290 Sauverny, Switzerland: Received 28-10-2016/ Accepted 30-01-2017: ABSTRACT: Context. The ﬁeld of exoplanet research is moving towards the detection and characterization of habitable planets. These exo-Earths can be easily found around low-mass stars by using either photometric transit or radial-velocity (RV) techniques. In the latter case the gain is twofold because the signal induced by the planet of a given mass is higher due to the more favourable planet-star mass ratio and because the habitable zone lies closer to the star. However, late-type stars emit mainly in the infrared (IR) wavelength range, which calls for IR instruments. Aims. SPIRou is a stable RV IR spectrograph addressing these ambitious scientiﬁc objectives. As with any other spectrograph, calibration and drift monitoring is fundamental to achieve high precision. However, the IR domain suﬀers from a lack of suitable reference spectral sources. Our goal was to build, test and ﬁnally operate a Fabry-P´erot-based RV-reference module able to provide the needed spectral information over the full wavelength range of SPIRou. Methods. We adapted the existing HARPS Fabry-P´erot calibrator for operation in the IR domain. After manufacturing and assembly, we characterized the FP RV-module in the laboratory before delivering it to the SPIRou integration site. In particular, we measured ﬁnesse, transmittance, and spectral ﬂux of the system. Results. The measured ﬁnesse value of F = 12.8 corresponds perfectly to the theoretical value. The total transmittance at peak is of the order of 0.5%, mainly limited by ﬁbre-connectors and interfaces. Nevertheless, the provided ﬂux is in line with the the requirements set by the SPIRou instrument. Although we could test the stability of the system, we estimated it by comparing the SPIRou Fabry-P´erot with the already operating HARPS system and demonstrated a stability of better than 1ms^−1 during a night. Conclusions. Once installed on SPIRou, we will test the full spectral characteristics and stability of the RV-reference module. The goal will be to prove that the line position and shape stability of all lines is better than 0.3m s^−1 between two calibration sequences (typically 24 hours), such that the RV-reference module can be used to monitor instrumental drifts. In principle, the system is also intrinsically stable over longer time scales such that it can also be used for calibration purposes. We can conclude that the presented RV-reference module for SPIRou is able to measure instrumental drifts at the required precision level and can replace the performance limited hollow-cathode lamps and absorption cells with respect to this goal. Furthermore, we identify possible developments of the module and signiﬁcant potential to convert it into a calibration source, which could turn the FabryP´erot-based light source into a cost-eﬀective alternative to laser-frequency combs, at least in the short and

a. midterm b. long term c. calibration d. cells

Q50. Vanderbilt University: “Particles from outer space are wreaking low-grade havoc on personal electronics: February 17, 2017:” Operational failures may be caused by the impact of electrically charged particles generated by cosmic rays that originate outside the solar system. This is a really big problem, but it is mostly invisible to the public, said Bharat Bhuva, professor of electrical engineering at Vanderbilt University, in a presentation on Friday, Feb. 17 at a session titled "Cloudy with a Chance of Solar Flares: Quantifying the Risk of Space Weather" at the annual meeting of the American Association for the Advancement of Science in Boston. When cosmic rays traveling at fractions of the speed of light strike the Earth's atmosphere they create cascades of secondary particles including energetic neutrons, muons, Pions and alpha particles. Millions of these particles strike your body each second. Despite their numbers, this subatomic torrent is imperceptible and has no known harmful effects on living organisms. However, a fraction of these particles carry enough energy to interfere with the operation of microelectronic circuitry. When they interact with integrated circuits, they may alter individual bits of data stored in memory. This is called a single-event upset or SEU. Since it is difficult to know when and where these particles will strike and they do not do any physical damage, the malfunctions they cause are very difficult to characterize. As a result, determining the prevalence of SEUs is not easy or straightforward. "When you have a single bit flip, it could have any number of causes. It could be a software bug or a hardware flaw, for example. The only way you can determine that it is a single-event upset is by eliminating all the other possible causes," Bhuva explained. There have been a number of incidents that illustrate how serious the problem can be, Bhuva reported. For example, in 2003 in the town of Schaerbeek, Belgium a bit flip in an electronic voting machine added 4,096 extra votes to one candidate. The error was only detected because it gave the candidate more votes than were possible and it was traced to a single bit flip in the machine's register. In 2008, the avionics system of a Qantus passenger jet flying from Singapore to Perth appeared to suffer from a single-event upset that caused the autopilot to disengage. As a result, the aircraft dove 690 feet in only 23 seconds, injuring about a third of the passengers seriously enough to cause the aircraft to divert to the nearest airstrip. In addition, there have been a number of unexplained glitches in airline computers - some of which experts feel must have been caused by SEUs - that have resulted in cancellation of hundreds of flights resulting in significant

a. outcome b. achievement c. benefit d. economics

Q51. Pramana – J. Phys. (2017) 88: 23 c Indian Academy of Sciences. ”Nonlinear waves in electron–positron–ion plasmas including charge separation”. A MUGEMANA, S MOOLLA and I J LAZARUS: Durban 4000, South Africa. E-mail: Moollas@ukzn.ac.za received 11 September 2015; revised 10 June 2016; accepted 20 July 2016; published online 4 January 2017: Abstract. Nonlinear low-frequency electrostatic waves in a magnetized, three-component plasma consisting of hot electrons, hot positrons and warm ions have been investigated. The electrons and positrons are assumed to have Boltzmann density distributions while the motion of the ions are governed by ﬂuid equations. The system is closed with the Poisson equation. This set of equations is numerically solved for the electric ﬁeld. The effects of the driving electric ﬁeld, ion temperature, positron density, ion drift, Mach number and propagation angle are investigated. It is shown that depending on the driving electric ﬁeld, ion temperature, positron density, ion drift, Mach number and propagation angle,the numerical solutions exhibit wave forms that are sinusoidal, saw-tooth and spiky. The introduction of the Poisson equation increased the Mach number required to generate the waveforms but the driving electric ﬁeld E₀ was reduced. The results are compared with satellite observations. We have studied nonlinear low-frequency waves in e–p–i plasma including charge separation. By using ﬂuid equations for the warm ions with Poisson’s equation, nonlinear electrostatic waves have been investigated in a plasma consisting of Boltzmann electrons and positrons. The effects of driving electric ﬁeld, ion temperature, positron density, ion drift velocity, Mach number and propagation angle were studied. The electric ﬁelds of the nonlinear waves were investigated and we have shown that for high positron density, the spiky structures are easier to generate. Our model also shows that the Mach number and the angle of propagation do not affect the nonlinearity of wave

a. disturbances b. numbers c. structures d. drifts.

Q52. Pramana – J. Phys. (2017) 88: 4 c Indian Academy of Sciences: On quantum harmonic oscillator being subjected to absolute potential state: SWAMI NITYAYOGANANDA: Ramakrishna Mission Ashrama, R.K. Beach, Visakhapatanam 530 003, India E-mail: nityayogananda@gmail.com: MS received 1 May 2015; accepted 6 May 2016; published online 3 December 2016: Abstract. In a quantum harmonic oscillator (QHO), the energy of the oscillator increases with increased frequency. In this paper, assuming a boundary condition that the product of momentum and position, or the product of energy density and position remains constant in the QHO, it is established that a particle subjected to increasing frequencies becomes gradually subtler to transform into a very high dormant potential energy. This very high dormant potential energy is referred to as ‘like-potential’ energy in this paper. In the process a new wave function is generated. This new function, which corresponds to new sets of particles, has scope to raise the quantum oscillator energy (QOE) up to inﬁnity. It is proposed to show that this high energy does not get cancelled but remains dormant. Further, it is proposed that the displacement about the equilibrium goes to zero when the vibration of the oscillator stops and then the QOE becomes inﬁnity – this needs further research. The more the QOE, the greater will be the degree of dormancy. A simple mathematical model has been derived here to discuss the possibilities that are involved in the QHO under the above-mentioned boundary conditions. In this paper the considered model gives scope for the existence of many subtler particles outside the Standard Model which ﬁll the Universe. These subtler particles, though having enormously high energy, remain inactive due to certain boundary conditions as stated in the paper. The energy of these particles does not get cancelled out but remains in a very dormant state termed in this paper as ‘like-potential’ state. A few such particles could be DE and dark matter. There could be even subtler particles than DE, whose existence has recently been anticipated by LHC physicists. It is hypothesized in this paper that the sesame subtle particles with their dormant state of energy become the source of other known particles, when the energy and the corresponding frequency of the particle come down to certain limit. The behaviour of these subtle particles is explained in this paper using the QHO under the speciﬁed boundary conditions. The state of these particles becomes more and more ‘like-potential’ and inactive as the displacement of the QHO is decreased with the increase of QOE. This way, when the energy of the QHO reaches inﬁnity, displacement goes to zero. This zero displacement state, which is nothing but no-vibration state, is described here as the pre-creation condition of the Universe. At this state, the energy stays inﬁnity but there is no movement in the oscillator. No creation is possible at this state. At this state, the space-time-vibration (causation) triad comes to absolute halt. Creation begins again when the same no-vibration QHO gets initial start-up to begin its ﬁrst vibration. The space and the time also get created along with

a. it b. universe c. world d. vibration

Q53. Pramana: J. Phys. (2017) 88: 18 c: Indian Academy of Sciences: ”Face-to-face interaction of multisolitons in spin-1/2 quantum plasma”: KAUSHIK ROY et al., Beluti M.K.M. High School, P.O.-Beluti, Dist-Birbhum, 731 301, India. E-mail: kaushikbolpur@rediffmail.com: MS received 7 May 2015; revised 26 March 2016; accepted 6 May 2016; published online 13 December 2016: Abstract. We investigate the face-to-face collision between multi-solitons in spin-1/2 quantum plasma. It is studied in the frame work of the model proposed by Marklundetal in Phys. Rev.E76, 067401(2007). This study is done with the help of the extended Poincare–Lighthill–Kno (PLK) method. The extended PLK method is also used to obtain two Korteweg–de Vries (KdV) equations and the phase shifts and trajectories during the head-on collision of multi-solitons. The collision-induced phase shifts (trajectory changes) are also obtained. The effects of the Zeeman energy, total mass density of the charged plasma particles, speed of the wave and the ratio of the sound speed to Alfvén speed on the phase shifts are studied. It is observed that the phase shifts are signiﬁcantly affected by all these parameters. We investigated face-to-face interaction of multi-solitons in spin-1/2 quantum plasma. We have considered essentially the collisions of multi-solitons (four, six) using a two-step method where we ﬁrst derived two different KdV equations using PLK method and then extracted multi-solution for each KdV equation using Hirota’s approach. Each soliton acquires two phase shifts, one due to head-on collision the other due to overtaking collision. The effect of the parameters involved in the nonlinear and dispersion coefﬁcient of the KdV equations on the amplitude of multi-solitons had been investigated, using PLK

a. variational method b. gauge method c. perturbation method d. soliton method.

Q54. Professor Steven P. Brown from the Department of Physics, with colleagues in the Department of Chemistry, have identified that the supramolecular structure of a guanosine derivative can be different upon passing from the solid state into the solution state and vice versa. This defies chemical precedent, as self-assembled structures driven by the formation of specific intermolecular hydrogen bonds in solution would be expected to remain the same in the solid state. The phenomenon was revealed by the state-of-the-art nuclear magnetic resonance (NMR) facility at Warwick. In solution state, the guanosine derivative analysed by the researchers is constituted by quartet-like molecular structure – and scientific intuition would suggests that this should remain like this in the solid state. However, upon changing into the solid state, the supramolecular assembly surprisingly contains both quartet and ribbon structures. Professor Brown and his colleagues made this discovery using advanced NMR spectroscopy technology, which measures the magnetic response of nuclei at the centre of atoms. The researchers identified the distinct supramolecular states by spotting varying peaks in spectra that identify close approach of these magnetic nuclei in atoms. Professor Brown comments: "Access to state-of-the-art NMR infrastructure has enabled us to see with chemical precision how the guanosine-based molecules self-assemble, thus revealing the surprising phenomenon of a change in self-assembly upon going changing from solution to solid and from solid to solution." Abstract: The formation of distinct supramolecular assemblies, including a metastable species, is revealed for a lipophilic guanosine (G) derivative in solution and in the solid state. Structurally different G-quartet-based assemblies are formed in chloroform depending on the nature of the cation, anion and the salt concentration, as characterized by circular dichroism and time course diffusion-ordered NMR spectroscopy data. Intriguingly, even the presence of potassium ions that stabilize G-quartets in chloroform was insufficient to exclusively retain such assemblies in the solid state, leading to the formation of mixed quartet and ribbon-like assemblies as revealed by fast magic-angle spinning (MAS) NMR spectroscopy. Distinct N−H⋅⋅⋅N and N−H⋅⋅⋅O intermolecular hydrogen bonding interactions drive quartet and ribbon-like self-assembly resulting in markedly different 2D ¹H solid-state NMR spectra, thus facilitating a direct identification of mixed assemblies. A dissolution NMR experiment confirmed that the quartet and ribbon interconversion is reversible–further demonstrating the changes that occur in the self-assembly process of a lipophilic nucleoside upon a solid-state to solution-state transition and vice versa. A systematic study for complexation with different cations (K⁺, Sr²⁺) and anions (picrate, ethanoate and iodide) emphasizes that the existence of a stable solution or solid-state structure may not reflect the stability of the same supramolecular entity in another

a. spectroscopy b. phase c. structure d. assembly

Q55. Relations Involving Static Quadrupole Moments of 2⁺ states and B(E2)’s: S. Yeager et al, Mississippi 39210: February 21, 2017: ABSTRACT: We deﬁne the “quadrupole ratio” r_Q = Q₀(S)/Q₀(B) where Q₀(S) is the intrinsic quadrupole moment obtained from the static quadrupole moment of the 2+1 state of an even-even nucleus and Q₀(B) the intrinsic quadrupole moment obtained from B(E2)_0→2. In both cases we assume a simple rotational formula connecting the rotating frame to the laboratory frame. The quantity r_Q would be one if the rotational model were perfect and the energy ratio E(4)/E(2) would be 10/3. In the simple vibrational model, r_Q would be zero and E(4)/E(2) would be two. There are some regions where the rotational limit is almost met and fewer where the vibrational limit is also almost met. For most cases, however, it is between these two limits, i.e. 0 < |r_Q| < 1. There are a few cases where r_Q is bigger than one, especially for light nuclei. In most cases the quadrupole ratio is positive but there are two regions with negative ratios. The ﬁrst case is that of light nuclei and the second has certain nuclei close to ²⁰⁸Pb. This work represents an expansion of the 2006 work of Robinson et al. We here consider essentially all nuclei where Q(2⁺) has been measured. Since that work, there have been other works of relevance e.g. that of Bertsch et al., in which the Gogny interaction was used to calculate Q(2⁺) and B(E2) as well as work by Sabbey et al. Early works using Skyrme H.F. were performed by Jaqaman et al. who also considered hexadecapole models. Recent work by Sarriguren et al., should be noted as well as the phase transitions in the platinum isotopes by Morales et al. They consider the heavier nuclei, isotopes of Yb, Hf, W, Os, and Pt, where there are many changes from prolate to oblate. Also mentioned in the 2006 work, Zelevinsky and Volya noted that with random matrices they obtained with a high probability that the quadrupole ratio r_Q (as we deﬁne it) is either one or zero. Why this is so is not

a. clear b. obvious c. marked d. evident.

Q56. [astro-ph.CO]: 19 Feb 2017: Supplying Dark Energy from Scalar Field Dark Matter: Merab Gogberashvili et al., Georgia, Alexander S. Sakharov, Switzerland: February 21, 2017: ABSTRACT: We consider the hypothesis that the dark matter consists of ultra-light bosons residing in the state of a Bose-Einstein condensate, which behaves as a single coherent wave rather than as individual particles. In galaxies, spatial distribution of scalar ﬁeld dark matter can be described by the relativistic Klein-Gordon equation on a background space-time with Schwarzschild metric. In such a setup, the equation of state of scalar ﬁeld dark matter is found to be changing along with galactocentric distance from dust-like (p = 0), inside the galactic halo, to vacuum-like (p = −ρ), in intergalactic space. We reveal the ranges of masses and self-interaction strengths of scalar ﬁeld that allow the Bose-Einstein condensate to supply both dark matter and dark energy components of the universe. We emphasize that the estimation (37) for the modulus of the SFDM in the outer galactic region is valid only for the Schwarzschild space-time and oscillatory time depended wave function. A similar requirements of the time evolution of the BEC wave function has been applied in, while the self-interaction imposed on the constituent ultra-light scalar boson was taken as attractive one. The value of the mass of the ultra-light bosons needed for realization of our scenario is of the same order of magnitude used in model, which also suggest that a macroscopic wave function of a BEC gives rise to a vacuum-like state which is typical for a positive cosmological constant. To explore cosmological features of our model one should use the Robertson-Walker metric and evolving in time scalar ﬁelds. Cosmological studies of the BEC DM show signiﬁcant diﬀerences with respect to the standard cosmology. Presence of such condensates could have modiﬁed drastically the cosmological evolution of the early universe, as well as the large scale structure formation process In summary, previously it has been shown in literature that bosons of tiny mass with repulsive self-interaction forming a BEC at early times may account for DM content of the universe. Provided that the BEC, being trapped inside galaxies, can be considered as a system posed into a space-time with Schwarzschild metric, we consider the behaviour of its macroscopic wave function characterized by oscillatory time dependence. We observed that for such a setup the strong energy condition is broken providing that vacuum-like equation of state at large galactocentric distances (in outer parts of galaxies). Thus, SFDM of ultra-light complex scalar ﬁeld, which can form large size BEC around galaxies with observed properties of the dark matter, could also supply the dark energy component of the

a. galaxy b. metric c. universe d. world

Q57. [physics.pop-ph] 20 Feb 2017 Qbe: Quark Matter on Rubik’s Cube ∗ T. Csorgo: Hungary February 22, 2017: ABSTRACT: Quarks can be represented on the faces of the 3x3 Rubik’s cube with the help of a symbolic representation of quarks and anti-quarks that was developed originally for a deck of elementary particle cards, called Quark Matter Card Game. Cubing the cards leads to a model of the nearly perfect ﬂuid of Quark Matter on Rubik’s cube, or Qbe, which can be utilized to provide hands-on experience with the high entropy density, overall colour neutrality and net baryon free, nearly perfect ﬂuid nature of Quark Matter. To illustrate that quite some time and wisdom might be needed to solve Qbe, let us estimate how many rotations might be needed in every second, if we would try to solve it just by random rotations. Our Universe is about 13.8 × 10⁹ years old and the number of states on Qbe is given as approximately 2.1× 10²⁴. As the lifetime of our Universe converts to about 4.35 × 10¹⁷ seconds, one would need to rotate the Qbe a little bit more than 4.8 million times in every second, for the entire lifetime of our Universe, to be able to solve it just by random rotations. Such a tremendous mindless eﬀort can be contrasted to the various records of solving Rubik’s cube using skilful means in speed cubing championships: The current world record for single time on a 3×3×3 Rubik’s Cube was set by Feliks Zemdegs of Australia in December 2016 with a time of 4.73 seconds at the POPS Open 2016 competition in Melbourne, Australia. Let us close this article by noting that what we discussed here was just a toy or a toy model that does not have to be taken too seriously. In this sense this outreach article is quite similar to many studies in science. A model is just a model, reﬂecting certain properties of the reality and is best understood with a certain smiling playfulness, similar to the mysterious smile on the face of Mona Lisa. The Road to Reality is often a diﬃcult one but our journey may become much more enjoyable, perspicacious and light some if we proceed with a touch of smiling

a. presentation b. wisdom c. clue d. thought

Q58. arXiv:1702.06454 [cond-mat.mes-hall]October 14, 2016: Compact Modelling of MOSFET I-V Characteristics and Simulation of Dose-Dependent Drain Currents: G. I. Zebrev et al. ABSTRACT: We have presented a compact MOSFET model, which allows us to describe the I-V characteristics of irradiated long channel and short-channel transistors in all operation modes at different measurement temperatures and interface trap densities. The model allows simulating of the off-state and the on-state drain currents of irradiated MOSFETs based on an equal footing. Particularly, a novel compact model of the rebound effect in the n-MOSFETs was employed for simulation of the total dose dependencies of drain currents in the highly scaled 60 nm node circuits irradiated up to 1Grad. Compatibility of the model parameter set with BSIM and a single closed form of the model equation imply the possibility of its easy implementation into the standard CAD tools. We have presented a concise description of the compact MOSFET physics-based model, which allows us to simulate the MOSFET I-V characteristics both for the long-channel and short-channel MOSFETs over a range of measurement temperatures. It has been shown that the model is suitable for accurate simulation of the MOSFET’s I-V characteristics over a wide operation temperature range in harsh environments such as ionizing irradiation with extremely high doses. The model has a closed analytical form with a restricted number of physical parameters, compatible with a standard set of BSIM and SPICE parameters, allowing easy embedding into standard CAD tools via implementation in

a. Verilog-A b. CAD tools c. MOSFET d. BSIM

Q59. Quantum Technology: Single-Photon Source: Author: Vincent Camus Master Nanotech 2011-2012 - Grenoble INP Phelma vincent.camus@phelma.grenoble-inp.fr. Defended in September 2012 Declassiﬁed in February 2017. An ideal single-photon source is a source that can emit at any arbitrary and deﬁned time (on-demand) and in which the probability of single photon emission is 100% and the probability of multiple-photon emission is 0%. Emitted photons are indistinguishable, repetition rate is arbitrarily fast. Deviations from these ideal characteristics. We imagine building single-photon sources from various systems: quantum dots, single atom, ion or molecule. Another possibility is to use a probabilistic system based on photon Spontaneous Parametric Downconversion (SPDC). Single-photon detectors based on single-photon avalanche photodiodes, photomultiplier tubes, superconducting nanowires are typically used as non-photon-number resolving detectors. They can only distinguish zero photon and more than zero photons, and they are the most commonly used single-photon detectors. Others are photon-number resolving detectors. While detecting a single photon is a very diﬃcult task, discriminating the number of incident photons is even more diﬃcult. One direct approach is simply to break the detector active area into distinct pixels and split the idler signal onto these pixel areas. Another approach is based on superconducting tunnel junction, but their complexity are high, their eﬃciencies are not very high, their resolution and speed are limited, and their working temperature (< 0.4 K) very

a. untenable b. limited c. low d. high

Q60.arXiv.1702.06721(cross-list from cond-mat.mes-hall): “Formation of Plasmon-Polariton Pulses in the Cooperative Decay of Excitons of Quantum Dots: Near a Metal Surface”: A.V. Shesterikov et al.,Russia (Dated: February 23, 2017): ABSTRACT: The formation of pulses of surface electromagnetic waves in a metal/dielectric interface is considered in the process of cooperative decay of excitons of quantum dots distributed near a metal surface in a dielectric layer. It is shown that the eﬃciency of exciton energy transfer to excited plasmons can be increased by selecting the dielectric material with speciﬁed values of the complex permittivity. It is found that in the mean ﬁeld approximation the semi-classical model of formation of plasmon pulses in the system under study is reduced to the pendulum equation with the additional term of nonlinear losses. The models presented in the paper can be useful for practical applications such as the development of plsamonic integrated circuits for quantum computations. In particular, considerated collective eﬀects can be used as a basis for multiqubits register initialization in the process of formation the quantum correlations between QD. The advantage of the realization of such a register in the plasmon-exciton systems to atomic-optical systems is the ability to implement an eﬀective addressing schemes by coupling of each quantum dot with localized plasmon modes on the nanoscale. Besides, important problems of the direct connection of such systems with all-optical data communication systems remain open. In particular, one of the problems is increasing the eﬃciency of mutually reversible conversion of the light wave ﬁeld and plasmon polaritons formed in layered structures. Final answers to these problems can be obtained in relevant experiments, in particular, using epiluminescence spectro-microscopy of single quantum

a. emitters b. Plasmon c. Epi-luminescence d. spectroscopy

Q61. PHYSICAL REVIEW D 95, 043006 (2017): “Neutrinos from type Ia supernovae: The gravitationally confined detonation scenario”: Warren P. Wright et al., and Astrophysics (CAASTRO) (Received 26 September 2016; published 21 February 2017) Despite their use as cosmological distance indicators and their importance in the chemical evolution of galaxies, the unequivocal identification of the progenitor systems and explosion mechanism of normal type I a supernovae (SNe Ia) remains elusive. The leading hypothesis is that such a supernova is a thermonuclear explosion of a carbon-oxygen white dwarf, but the exact explosion mechanism is still a matter of debate. Observation of a galactic SN Ia would be of immense value in answering the many open questions related to these events. One potentially useful source of information about the explosion mechanism and progenitor is the neutrino signal because the neutrinos from the different mechanisms possess distinct spectra as a function of time and energy. In this paper, we compute the expected neutrino signal from a gravitationally confined detonation (GCD) explosion scenario for a SN Ia and show how the flux at Earth contains features in time and energy unique to this scenario. We then calculate the expected event rates in the Super-K, Hyper-K, JUNO, DUNE, and Ice Cube detectors and find both Hyper-K and Ice Cube will see a few events for a GCD supernova at 1kpc or closer, while Super-K, JUNO, and DUNE will see events if the supernova is closer than∼0.3kpc. The distance and detector criteria needed to resolve the time and spectral features arising from the explosion mechanism, neutrino production, and neutrino oscillation processes are also discussed. The neutrino signal from the GCD is then compared with the signal from a deflagration-to-detonation transition (DDT) explosion model computed previously. We find the overall event rate is the most discriminating feature between the two scenarios followed by the event rate time structure. Using the event rate in the Hyper-K detector alone, the DDT can be distinguished from the GCD at 2σ if the distance to the supernova is less than 2.3kpc for a normal mass ordering and 3.6kpc for an inverted ordering. The results show that the GCD SN Ia produces two neutrino bursts. The first is associated with deflagration burning with a peak luminosity of 2.3 × 10⁴⁸ erg/s at t=0.45 s. The second burst is associated with detonation burning with a peak luminosity of 1.2 × 10⁴⁸ erg/s at t=2.82 s. There is very little neutrino emission in between the two bursts. We also find a 10MeV ν_e spectral feature associated with electron capture on copper appears at∼1s during the deflagration burst which persists for the entirety of the detonation burst. Neutrino oscillations introduce significant flavour conversion and are very line-of-sight dependent due to the discontinuity-ridden density profile and the asymmetrical explosion. The oscillations also deviate from adiabatic evolution across much of the time and energy parameter space. However, even though the oscillations show large line of-sight dependence, the effect of line-of-sight variation on the total number of detected events is only a few percent. And finally, SN Ia can also provide information about neutrino properties if the explosion mechanism and distance are known. We find, if the mechanism and distance are known, the overall event rate can be used to determine the neutrino mass

a. oscillations b. deflagration c. ordering d. splitting

Q62. Astronomers propose a cell phone search for galactic fast radio bursts: Date: February 14, 2017: Harvard-Smithsonian Centre for Astrophysics: Fast radio bursts seem to come from distant galaxies, but there is no obvious reason that, every once in a while, an FRB wouldn't occur in our own Milky Way galaxy too. If it did, astronomers suggest that it would be 'loud' enough that a global network of cell phones or small radio receivers could 'hear' it. 25 Feb 2017: Previous FRBs were detected at radio frequencies that match those used by cell phones, Wi-Fi, and similar devices. Consumers could potentially download a free smartphone app that would run in the background, monitoring appropriate frequencies and sending the data to a central processing facility. "An FRB in the Milky Way, essentially in our own back yard, would wash over the entire planet at once. If thousands of cell phones picked up a radio blip at nearly the same time, that would be a good sign that we've found a real event," explains lead author Dan Maoz of Tel Aviv University. Finding a Milky Way FRB might require some patience. Based on the few, more distant ones, that have been spotted so far, Maoz and Loeb estimate that a new one might pop off in the Milky Way once every 30 to 1,500 years. However, given that some FRBs are known to burst repeatedly, perhaps for decades or even centuries, there might be one alive in the Milky Way today. If so, success could become a yearly or even weekly event. A dedicated network of specialized detectors could be even more helpful in the search for a nearby FRB. For as little as $10 each, off-the-shelf devices that plug into the USB port of a laptop or desktop computer can be purchased. If thousands of such detectors were deployed around the world, especially in areas relatively free from Earthly radio interference, then finding a close FRB might just be a matter of

a. research b. serious thought c. time d. effort

Q63. 13 January 2017 Energy-Dissipative Matrices Enable Synergistic Toughening in Fibre Reinforced Soft Composites; Authors: Yiwan Huang et al; updated 27 February 2017: Abstract: Tough hydrogels have shown strong potential as structural biomaterials. These hydrogels alone, however, possess limited mechanical properties (such as low modulus) when compared to some load-bearing tissues, e.g., ligaments and tendons. Developing both strong and tough soft materials is still a challenge. To overcome this obstacle, a new material design strategy has been recently introduced by combining tough hydrogels with woven fiber fabric to create fiber reinforced soft composites (FRSCs). The new FRSCs exhibit extremely high toughness and tensile properties, far superior to those of the neat components, indicating a synergistic effect. Here, focus is on understanding the role of energy dissipation of the soft matrix in the synergistic toughening of FRSCs. By selecting a range of soft matrix materials, from tough hydrogels to weak hydrogels and even a commercially available elastomer, the toughness of the matrix is determined to play a critical role in achieving extremely tough FRSCs. This work provides a good guide toward the universal design of soft composites with extraordinary fracture resistance capacity. When used alone, the fibre-reinforced hydrogels developed by the team are 25 times tougher than glass fibre fabric, and 100 times tougher than hydrogels – in terms of the energy required to destroy them. Combining these materials enables a synergistic toughening. The team theorizes that toughness is increased by dynamic ionic bonds between the fibre and hydrogels, and within the hydrogels, as the fibre’s toughness increases in relation to that of the hydrogels. Consequently, the newly developed hydrogels are 5 times tougher compared to carbon

a. steel b. shield c. hold d. covering.

Q64.arXiv:1703.00127v1 [cond-mat.mtri-sci]; ”Infrared properties of micro-machined vanadium oxide thin films”: Martin Rees, Haifei Wang, Thomas Decker, Robinson L. Smith Rio Salado College, Tempe, AZ, USA: ABSTRACT: This paper discusses questions of synthesizing and pressing vanadium oxides to create film-forming materials that can be used in producing optical coatings. Based on the film-forming materials thus created, technological processes have been developed for fabricating coatings from vanadium dioxide by two methods of producing thin films: vacuum evaporation and magnetron sputtering. Questions of using films made from vanadium oxide in optical instrumentation are considered. An analysis of the optical characteristics of single layers of vanadium dioxide when they undergo a phase transition showed that their changes are very different in the visible, near- and mid-IR regions. As can be seen from the table, the strongest changes of optical constants n and k are observed in the spectral interval 9–11 m, where they take the maximum values in the metallic phase. However, it is obvious that single films of vanadium dioxide have a limited modulation depth in both reflected and in transmitted light. A numerical analysis of the possibilities of increasing the contrast of the reflectance changes of single layers of vanadium dioxide showed that the bi-stable properties can be improved by depositing them on highly reflective metallic

a. reflectors b. shields c. mirrors d. sheets.

Q65. arXiv: 1703.00217 [cond-mat-supr-com]: 1 March 2017: Observation of pseudogap in MgB₂: Patil S. et al: Genova, Italy. ABSTRACT: Pseudo-gap phase in superconductors continues to be an outstanding puzzle that differentiates unconventional superconductors from conventional ones (BCS-superconductors). Employing high resolution photoemission spectroscopy on a highly dense conventional superconductor, MgB₂, we discover an interesting scenario. While the spectral evolution close to the Fermi energy is commensurate to BCS descriptions as expected, the spectra in the wider energy range reveal emergence of a pseudo-gap much above the superconducting transition temperature indicating apparent departure from the BCS scenario. The energy scale of the pseudo-gap is comparable to the energy of E_2g phonon mode responsible for superconductivity in MgB₂ and the pseudo-gap can be attributed to the eﬀect of electron-phonon coupling on the electronic structure. These results reveal a scenario of the emergence of the superconducting gap within an electron-phonon coupling induced pseudo-gap. In summary, we have studied the electronic structure of MgB₂ employing high resolution photoemission spectroscopy. Our high resolution valence band photoemission results on a highly dense sample show the existence of a pseudo-gap in MgB₂ below 200 K and a superconducting gap below Tc. The energy scale over which the pseudo-gap forms (∼65-70meV) is signiﬁcantly larger than the energy scale of the superconducting gap (∼4-6meV) and corroborates well with the E_2g phonon excitations of the system. A probable picture of superconductivity in MgB₂ can be conjectured to be the one where the electron pairs causing superconductivity emerges from the electron-phonon coupled species already formed above

a. Tb b. Tc c. Td d. Te

Q66. Prepared for submission to JCAP: Cosmological histories in bimetric gravity: A graphical approach: E. M¨ortsella, et al: Stockholm, Sweden: E-mail: edvard@fysik.su.se:ABSTRACT: The bimetric generalization of general relativity has been proven to be able to give an accelerated background expansion consistent with observations. Apart from the energy densities coupling to one or both of the metrics, the expansion will depend on the cosmological constant contribution to each of them, as well as the three parameters describing the interaction between the two metrics. Even for ﬁxed values of these parameters can several possible solutions, so called branches, exist. Diﬀerent branches can give similar background expansion histories for the observable metric, but may have diﬀerent properties regarding, for example, the existence of ghosts and the rate of structure growth. In this paper, we outline a method to ﬁnd viable solution branches for arbitrary parameter values. We show how possible expansion histories in bimetric gravity can be inferred qualitatively, by picturing the ratio of the scale factors of the two metrics as the spatial coordinate of a particle rolling along a frictionless track. A particularly interesting example discussed is a speciﬁc set of parameter values, where a cosmological dark matter background is mimicked without introducing ghost modes into the theory. We applied the method to a small selection of parameter values, and found examples of re collapsing solutions (Bi = 1), as well as solutions with the background expansion resembling the observed accelerated expansion, but plagued by space time singularities and scalar linear instabilities (B1 = B4 = 1). Most interestingly, we revisited a model being able to mimic the background evolution of a Ωm,0 = 0.3 and ΩΛ = 0.7 model using baryonic matter only (B1 = B3 = 0). Allowing for negative values of r, the model has stable linear scalar perturbations, no metric singularities at the background level and is not plagued by the Higuchi ghost. It would be of interest to study closer this, and related models, with respect to, e.g., the full evolution of scalar and tensor perturbations, the impact of the energy scaling on radiation dominated epochs and the Vainshtein

a. principle b. criteria c. Suggestion d. mechanism

Q67.arXiv:1703.00036[quant-ph]: Huygens’ principle and Dirac-Weyl equation: Saverio Pascazio, Francesco V. Pepe, and Juan Manuel P´erez-Pardo; Italy and Spain (Dated: March 2, 2017): ABSTRACT: We investigate the validity of Huygens’ principle for forward propagation in the massless Dirac Weyl equation. The principle holds for odd space dimension n, while it is invalid for even n. We explicitly solve the cases n = 1, 2 and 3 and discuss generic n. We compare with the massless Klein-Gordon equation and comment on possible generalizations and applications. We worked with retarded boundary conditions for the Green function, propagating solutions forward in time. This option is particularly suited for the investigation of electron motion in graphene, close to Dirac’s points, where the description via a two-component spinor wave function in two space dimensions is very eﬀective. There are other interesting applications that one can consider, such as the quantum simulations of QED and in general lattice gauge theories and low-dimensional quantum systems. The diﬀerences between, say, n = 1 and 2, might display interesting signatures of bulk vs boundary eﬀects in the propagation of physical observables. There are a number of problems that one can investigate in the future. One of these is the extension of these ideas to the massive Dirac equation. Another interesting problem would be to unveil the eﬀects of dimensionality when an external ﬁeld is introduced via the minimal coupling prescription. In general, this bears consequences on the way the coupling to external classical ﬁelds is handled. Finally, an important open question is the relationship among Huygens principle, dimensionality and Feynman’s prescription for the propagator. A natural question that arises is whether one can deﬁne a Huygens-like principle for a properly quantized theory, describing the propagation of quantum particles and antiparticles in 3+1 dimensions. For instance, it would be interesting (and intriguing) to understand whether Feynman’s prescription for the propagator preserves or rather prevents the validity of Huygens’ principles, and which role is played by space dimensionality.

a. complexity b. dimensionality c. system d. orientation

Q68. CURRENT SCIENCE, VOL. 112, NO. 3, 10 FEBRUARY 2017: Barsha R. Goswami et al., Mahi, a unique herbal ink prepared with cow urine as extractant, was used for manuscript writing in early Assam. The ink had a deep and fast colour and was persistent on Sancipat manuscripts due to its resistance to aerial oxidation and fungi. The non-destructive nature of Mahi is proven by tens of thousands of centuries old Sancipat (a cellulosic folios made of bark of sanci tree, Aquilaria agallocha) manuscripts, a testimony of the rich literary and socio-cultural heritage, still existing in Assam without losing the glaze of the ink. For preparation of Mahi, fruit-pulp of hilikha (Terminalia chebula), amlakhi (Emblica officinalis) and bhomora (Terminalia belerica), the bark of hilikha, bhomora, mango (Magnifera indica), jamuk (Eugenia jambolana), bahat (monkey jack, Artocarpus lakoocha); and the whole herb of keharaj (Eclipta alba), Bar manimuni (Centella asiatica) and sharu manimuni (Hydrocoryl rotundifolia) were mashed together and soaked in cow urine in a new earthen pot during the foggy winter season and kept away from direct sunlight. The raw materials varied depending upon availability. Red hot iron tool was dipped into the mixture. Rust of iron nail or blood of kuchiya (Monopterus cuchia, a kind of eel) or hirakoch (Pangasius sutchi, a kind of cat fish) was also added. Drops of clear Mahi percolate through the bottom of the earthen pot in 9–10 days. There is hardly any scientific report available in the literature on the preparation and properties of Mahi and its possible contribution to the survival of Sancipat manuscripts for centuries in the hot and humid climate of Assam. The present study was aimed at analysing the physico-chemical properties of Mahi, including its special properties. The study includes phytochemical analysis, antimicrobial assay, UV–visible with fluorescence analysis, iron and copper estimation and identification, by HPLC-UV some

a. polyphenols b. Sancipats c. cow urine d. Keharaj herb.

Q69. MNRAS 000, 1–11 (2017) Preprint 23 March 2017: Dark matter haloes in modiﬁed gravity and dark energy: interaction rate, small-, and large-scale alignment: by Benjamin L’Huillier et al., Accepted 2017 March 20. Received 2017 March 16; in original form 2016 October 24. ABSTRACT We study the properties of dark matter haloes in a wide range of modiﬁed gravity models, namely, f(R), DGP, and interacting dark energy models. We study the eﬀects of modiﬁed gravity and dark energy on the internal properties of haloes, such as the spin and the structural parameters. We ﬁnd that f(R) gravity enhance the median value of the Bullock spin parameter, but could not detect such eﬀects for DGP and coupled dark energy. f(R) also yields a lower median sphericity and oblateness, while coupled dark energy has the opposite eﬀect. However, these eﬀects are very small. We then study the interaction rate of haloes in diﬀerent gravity, and ﬁnd that only strongly coupled dark energy models enhance the interaction rate. We then quantify the enhancement of the alignment of the spins of interacting halo pairs by modiﬁed gravity. Finally, we study the alignment of the major axes of haloes with the largescale structures. The alignment of the spins of interacting pairs of haloes in DGP and coupled dark energy models show no discrepancy with GR, while f(R) shows a weaker alignment. Strongly coupled dark energy shows a stronger alignment of the halo shape with the large-scale structures. The fact that very large volumes are needed to detect any deviation from GR shows the weakness of the signal. For instance, in case of the alignment with the LSS, the largescale alignment is largely unaﬀected by modiﬁed gravity. Therefore, one can argue that treatments of intrinsic alignment based on GR should not induce bias in the analysis. The strength of our study is to apply the same method to several sets of simulations with diﬀerent gravity models, box size, and resolutions. This is the ﬁrst study devoted to the study of the small- and large-scale alignment in modiﬁed gravity and dark energy

a. assemblies b. deviation c. structures d. models

Q70.arXiv:1703.07563 [astro-ph.SR]: ESO 2017 Thursday 23 March, 2017 at 00:41: Astronomy & Astrophysics manuscript no. CME˙gamma˙sep˙v7 c: “The magnetic connectivity of coronal shocks to the visible solar surface during long-duration γ-ray events; I. Plotnikov et al”: ABSTRACT: Context. Solar ϒ ray events measured near Earth can last several hours during so-called Long Duration Gamma Ray Flares (LDGRFs). LDGRFs suggest that a particle-acceleration mechanism operates over many hours to produce energetic protons that stream continually towards the solar surface. Coronal shocks, driven by the expansion of Coronal Mass Ejections (CMEs), could be the source of these energetic particles. For this hypothesis to work, the shock must be magnetically connected to the solar disk visible from Earth in order for particles accelerated at the shock to be channelled towards and impact the visible chromosphere. LDGRFs that occur when solar eruptions erupt on the far side of the Sun and during which the ﬂare loops and foot points are not visible from Earth, provide favourable case studies to isolate the possible role of shocks driven by CMEs in producing the LDGRFs. Aims. In this paper, we investigate if the spatial and temporal evolution of the coronal shocks, inferred from stereoscopic observations, could be the accelerators of the particles producing the LDGRFs. Methods. We analyse three CMEs that (1) erupted behind the solar limb viewed from Earth, (2) were associated with the early formation of coronal shocks measured by ground-based radio spectrographs, and (3) were associated with γ−ray events measured by the Fermi-Large Area Telescope (LAT) instrument. A 3D triangulation technique, based on remote-sensing observations is employed to model the expansion of these three CME shocks from above the solar surface to the upper corona. Coupling the expansion model to diﬀerent models of the coronal magnetic ﬁeld allows us to derive the time-dependent distribution of shock Mach numbers and the magnetic connection of particles produced by the shock to the solar surface visible from Earth. Results. For all events, the reconstructed shock front was magnetically connected to the visible solar surface after the start of the ﬂare and just before the onset of the > 100MeV gamma-ray emission observed by Fermi-LAT γ-ray emission. The shock surface also exhibits supercritical Mach numbers required for signiﬁcant particle energisation. The strongest gamma-ray emissions occur when the ﬂanks of the shock exhibiting a quasi-perpendicular geometry are connected to the visible surface. Conclusions. This study provides further evidence that the high-energy protons producing the long duration high-energy γ-ray emission has the same CME shock origin as the Solar Energetic Particles observed in interplanetary space. RAD detector is sensitive to 1−1000MeV protons and 0.2−100MeV electrons but the counts from different energy bands and particle species are very technical to retrieve from the public data on the Planetary Data System depository. Here, we plot the “all included” energetic particle count rate. It is equivalent to the dose rate received by the detector. Bearing in mind that we do not distinguish between diﬀerent particle species we assumed that ﬁrst arriving particles were either the relativistic electrons or most energetic protons. While this procedure provides only limited information compared to the previously discussed 1 AU measurements, we use it here to illustrate the wide longitudinal spread of high particle ﬂuxes measured in the inner heliosphere rapidly after the onset of the solar eruptions. All three events were clearly detected on the Martian surface even though Mars was not always well connected magnetically to the ﬂare site. Mars was well connected to the eruption sites of the 2013 Oct 11 and 2014 Jan 06 events and was poorly connected on 2014 Sep 01 site (≥150 degrees away). This is reﬂected in the relatively fast, 3–4 hours, rise times for the two well connected events and the much longer rise time of the 2014 September event. It is interesting that the particle increases for the three events all started 30 minutes to 1 hour after the accompanying ﬂares. This suggests that some particles had prompt access to the ﬁeld lines reaching Mars even though the ﬂare site might be over

a. 50 b.100 c. 200 d. 150 degrees away.

Q71.arXiv:1703.10625v1 [astro-ph.SR]: 30 March 2017: The Sirius System and its Astrophysical Puzzles: Hubble Space Telescope and Ground-Based Astrometry: Howard E. Bond, et al. ABSTRACT: Sirius, the seventh-nearest stellar system, is a visual binary containing the metallic-line A1 V star Sirius A, brightest star in the sky, orbited in a 50.13-year period by Sirius B, the brightest and nearest white dwarf (WD). Using images obtained over nearly two decades with the Hubble Space Telescope (HST), along with photographic observations covering almost 20 years, and nearly 2300 historical measurements dating back to the 19th century, we determine precise orbital elements for the visual binary. Combined with the parallax and the motion of the A component, these elements yield dynamical masses of 2.063 ± 0.023M⊙ and 1.018 ± 0.011M⊙ for Sirius A and B, respectively. Our precise HST astrometry rules out third bodies orbiting either star in the system, down to masses of ∼15–25MJup. The location of Sirius B in the H-R diagram is in excellent agreement with theoretical cooling tracks for WDs of its dynamical mass, and implies a cooling age of ∼126Myr. The position of Sirius B in the mass-radius plane is also consistent with WD theory, assuming a carbon-oxygen core. Including the pre-WD evolutionary timescale of the assumed progenitor, the total age of Sirius B is about 228 ± 10Myr. We calculated evolutionary tracks for stars with the dynamical mass of Sirius A, using two independent codes. We ﬁnd it necessary to assume a slightly sub-solar metallicity, of about 0.85Z⊙, to ﬁt its location in the luminosity-radius plane. The age of Sirius A based on these models is about 237–247 Myr, with uncertainties of ±15 Myr, consistent with that of the WD companion. Elements of Relative Visual Orbit of Sirius (J2000) Element Value: Orbital period, P [yr] 50.1284 ± 0.0043 Semimajor axis, a [arcsec] 7.4957 ± 0.0025 Inclination, i [deg] 136.336 ± 0.040 Position angle of node, Ω [deg] 45.400 ± 0.071 Date of periastron passage, T0 [yr] 1994.5715 ± 0.0058 Eccentricity, e 0.59142 ± 0.00037 Longitude of periastron, ω [deg] 149.161 ± 0.075: Dynamical Masses for Sirius System: This paper: Total mass, MA + MB 3.20 M⊙ 3.196 ± 0.083 M⊙ 3.081 ± 0.034 M⊙ Mass of Sirius A, MA 2.15 M⊙ 2.143 ± 0.056 M⊙ 2.063 ± 0.023 M⊙ Mass of Sirius B, MB 1.05 M⊙ 1.053 ± 0.028 M⊙ 1.018 ± 0.011 M⊙. We discuss astrophysical puzzles presented by the Sirius system, including the probability that the two stars must have interacted in the past, even though there is no direct evidence for this, and the orbital eccentricity remains

a. high b. low c. intermediate d. uncertain

Q72. arXiv:1704.00747v1 [gr-qc] 3 Apr 2017: A new length scale for quantum gravity - and a resolution of the black hole information loss paradox Tejinder P. Singh Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India. tpsingh@tifr.res.in ABSTRACT: We show why and how Compton wavelength and Schwarzschild radius should be combined into one single new length scale, which we call the Compton-Schwarzschild length. Doing so oﬀers a resolution of the black hole information loss paradox, and suggests Planck mass remnant black holes as candidates for dark matter. It also compels us to introduce torsion, and identify the Dirac ﬁeld with a complex torsion ﬁeld. Dirac equation, and Einstein equations, are shown to be mutually dual limiting cases of an underlying gravitation theory which involves the Compton-Schwarzschild length scale, and includes a complex torsion ﬁeld. March 31, 2017: Essay written for the Gravity Research Foundation 2017 Awards for Essays on Gravitation. A common mathematical language is highly desirable, and is in fact provided by the Newman-Penrose formalism, where the Riemann tensor is expressed in terms of the so-called Ricci rotation coeﬃcients, using the so-called Ricci identities. When this is done, the Einstein equations begin to look remarkably similar to Dirac equations written in the same formalism. Motivated by this similarity, we made the radical suggestion that the Dirac spinors be identiﬁed with Ricci rotation coeﬃcients. Dirac equations can then be written in a manner similar to Einstein equations, with the Dirac mass acting as a source for the Ricci coeﬃcients. This however comes at a price. The Dirac equations land up satisfying severely undesirable constraints. Remarkably enough, the constraints all disappear entirely if one introduces torsion in the space-time, and identiﬁes the Dirac ﬁeld with the complex torsion part of the rotation coeﬃcients. This is independent support for torsion, which supplements the geometric motivation we gave above. We thus have gravity, described by the torsion free part of the Ricci coeﬃcients, and the Dirac ﬁeld, which is described by the torsion part. This seems like a nice way to bring together gravity and quantum theory, but while this has been done, earlier on we did not have the newly discovered length scale LCS and the related action principle. In forthcoming work we will cast this new action principle in the Newman-Penrose formalism, and investigate closely the consequences of this duality between torsion and gravity. Black holes mysteriously appear similar to elementary particles, both possessing the same set of conserved charges: mass, electric charge, and angular momentum. In fact it is known that all black hole solutions belong to Petrov Class D, whereas the Dirac particles are in a sense duals of this Petrov type. However, up until now, this similarity/duality only seemed like a

a. complexity b. coincidence c. jugglery d. accident

Q73. arXiv:1405.3915v1 [gr-qc]: 15 May 2014: How the quantum emerges from gravity: Anushrut Sharma∗ and Tejinder P. Singh† ∗Indian Institute of Technology Bombay, Powai, Mumbai 400076, India, †Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India, email addresses: anushrut@iitb.ac.in, tpsingh@tifr.res.in: The work of TPS is supported by a grant from the John Templeton Foundation [# 39530]. ABSTRACT: The dynamics equation or by the Kerr solution of Einstein equations. However, one does not know a priori as to which of the two systems of equations should be used in a given situation, and the choice is dictated by experiments. It is expected that the Dirac equation holds for microscopic masses, and the Kerr solution for macroscopic masses. This suggests that Einstein gravity and the Dirac theory are limiting cases of a common underlying theoretical framework. Here we propose that such a framework is provided by a geometric theory of gravity on a Riemann-Cartan space-time, which includes torsion. The Dirac equation emerges as the torsion dominated, gravity-free limit of this framework. March 31, 2014: This essay received an honourable mention in the Gravity Research Foundation 2014 Essay Contest. In the domain between Einstein gravity and Dirac theory, lies unchartered territory, where m ∼ mPl, and both G and ~ make their appearance. The source for the Riemann tensor is a combination of the matter energy-momentum tensor and the complex torsion term of the type imcκ/~, with the latter being possibly related to intrinsic spin. The theory bears resemblance to the Einstein-Cartan-Sciama-Kibble theory. with one important diﬀerence: ~ is now explicitly present in the ﬁeld equations, and torsion is complex. It is possible that the nonrelativistic limit of the theory is a non-linear Schrodinger equation which might help verify/rule out the hypothesis that the collapse of the wave-function during a quantum measurement is caused by gravity. This particular feature is amenable to currently ongoing experimental tests and its experimental investigation serves also as a test for the idea proposed in this essay. During the last century, many eminent physicists have emphasized the highly restrictive nature of a symmetric connection, and the possible fundamental signiﬁcance that the skew-symmetric part of the connection (torsion) might hold. Noteworthy amongst them is Schrodinger, who highlights this aspect essentially throughout his insightful book Space-time structure and in particular suggests on, the possibility of a geometric, torsion-oriented description of matter (see also Sciama). Where we have added a new aspect is in suggesting a complex torsion, cast in the modern language of the Newman-Penrose formalism, and this complex feature permits emergence of quantum theory in a manner not quite feasible for a real (fully classical) geometric theory. In the light of current ongoing experiments on gravity induced wave-function collapse, this family of ideas is worth

a. reinvestigating b. refreshing c. refreshing d. revisiting

Q74.arXiv:1403.2231. Quantum Physics (quant-ph): A possible correspondence between Ricci identities and Dirac equations in the Newman-Penrose formalism: Towards an understanding of gravity induced collapse of the wave-function? Anushrut Sharma∗ and Tejinder P. Singh† ∗Indian Institute of Technology Bombay, Powai, Mumbai 400076: †Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India: email: anushrut@iitb.ac.in, tpsingh@tifr.res.in: ABSTRACT: It is well-known that in the Newman-Penrose formalism the Riemann tensor can be expressed as a set of eighteen complex ﬁrst-order equations, in terms of the twelve spin coeﬃcients, known as Ricci identities. The Ricci tensor herein is determined via the Einstein equations. It is also known that the Dirac equation in a curved spacetime can be written in the Newman-Penrose formalism as a set of four ﬁrst-order coupled equations for the spinor components of the wave-function. In the present article we suggest that it might be possible to think of the Dirac equations in the N-P formalism as a special case of the Ricci identities, after an appropriate identiﬁcation of the four Dirac spinor components with four of the spin coeﬃcients, provided torsion is included in the connection, and after a suitable generalization of the energy-momentum tensor. We brieﬂy comment on similarities with the Einstein-Cartan-Sciama-Kibble theory. The motivation for this study is to take some very preliminary steps towards developing a rigorous description of the hypothesis that dynamical collapse of the wave-function during a quantum measurement is caused by gravity.This suggests some similarity between the spin coeﬃcients and spin, since in the ﬁrst case the extra terms are the spin tensor components and in the second case they are the spin coeﬃcients. Moreover, the spin coeﬃcients are anti-symmetric in the ﬁrst two indices just like the spin-tensor components. Another motivation for considering gravity as a mediating process in wave-function collapse is the following premise. The gravitational ﬁeld (i.e. the Coulomb part, not the gravitational wave) is inseparable from its matter source. It is hence reasonable to require that any physical process which explains dynamical collapse and localization of the material particle should also simultaneously account for its accompanying classical gravity ﬁeld. Thus the involvement of the “quantum gravitational ﬁeld” of the quantum object, as it approaches the macroscopic regime, is strongly indicated in the localization process. This also suggests that quantum gravity and the quantum measurement problem have a lot to do with each other. One could even push the argument further and note that since wave-function collapse is a non-linear process, some sort of non-linearity should be inherent in a quantum theory of

a. measurement b. localization c. gravity d. torsion

Q75. Japan’s Belle-II experiment a massive collaboration of 700 scientists from across the globe, an intense electron-positron beam made to collide to generate huge number of B-Mesons, the so-called beauty quark. Indian built fourth layer of the six layer silicon vertex detector, SVD, with the required analysis and theory, the largely miniaturised sensor engineering and the origami chip-on sensor helps to improve the signal to noise ratio. The strips from one side of the silicon micro-strip sensors are connected to a flexible electrical circuit which in turn connected to read-out chips. This folding over enables to place the readout chips as close as possible to the strips to reduce noise. Belle-II is fifty more sensitive than its predecessor and designed to measure the charged particles passing through it to accuracy of 15-20 microns (human hair thickness is 100 microns). This experiment has the same aim as the LHCb experiment at CERN and expected to reveal secrets for “New Physics”. The group at IMSC focuses on decays in which the beauty quark within a meson changes to a different flavour of quark called the Strange Quark. The high-energy accelerator research organization, KEK, in Japan is getting ready to launch Belle-II experiments. The few collisions create pairs of beauty particles. Beauty particles fly a few inches and then decay into other particles. Measuring the life-time of beauty particles is important, to understand Physics beyond the Standard Model. Tuning the colliding electron-positron beams to the upsilon 4S resonance (which decays into B pairs) and complementing the measurements with studies on the neighbouring electron-positron continuum (to estimate background), each group finds about 60 excess leptons. Unearthing the quark transition parameters needs a model to describe the overall decays, and there are several on the market. But broadly speaking the results show that there is about a ten per cent chance that a beauty quark will decay directly into a light quark, rather than via a charmed quark. The interpretation of these quark decay parameters remains a challenge to theorists.
a. theorists b. experimentalists c. thinkers d. inventors.

Q76. arXiv:1407.1457v2 [gr-qc] 20 Nov 2014: Negative mass bubbles in de Sitter space-time. Saoussen Mbarek∗† and M. B. Paranjape‡ Groupe de physique des particules, Département de physique, Université de Montréal, C.P. 6128, succ. centre-ville, Montréal, Québec, Canada, H3C 3J7: ABSTRACT: We study the possibility of the existence of negative mass bubbles within a de Sitter space-time background with matter content corresponding to a perfect ﬂuid. It is shown that there exist conﬁgurations of the perfect ﬂuid, that everywhere satisfy the dominant energy condition, the Einstein equations and the equations of hydrostatic equilibrium, however asymptotically approach the exact solution of Schwarzschild-de Sitter space-time with a negative mass. We have shown that there exist very physical conﬁgurations of an ideal ﬂuid which give rise to solutions of the Einstein equations that correspond asymptotically to negative mass Schwarzschild-de Sitter space times. The energy-momentum tensor that gives rise to such space times is perfectly physical, it everywhere satisﬁes the dominant energy condition. Since the space time is not asymptotically ﬂat, we evade the positive energy theorems which would not allow for negative mass. Negative mass conﬁgurations therefore can exist in de Sitter backgrounds, exactly as have been proposed for the inﬂationary phase of the early universe. If a mechanism for production of pairs of particles with positive and negative mass can be determined, in the early universe there would be a plasma of positive and negative mass particles. Such a plasma would in principle cause an effective screening of gravitational waves, being essentially opaque for frequencies below the plasma frequency.

a. domain b. switch c. frequency d. threshold.

Q77. On 12 May 2016:at 4:34 PM: Particle colliders have gotten very, very big, but some collider projects around the world are growing more ingenious just as quickly as the Large Hadron Collider is becoming more powerful. There are colliders that smash together special types of particles, or which smash together particles using only a specific type of controlling energy. But now, a team of German scientists has published a study in Nature describing their new form of collider, which can smash so-called “quasiparticles” together. With the new tool, scientists could study the interactions of things like excitons and “electron holes.” Quasiparticles are the name we give to certain patterns of behaviour in regular particles, in essence, they don’t exist. But engineering is a lot easier if we act as though they do. An electron hole, for instance, is a stable, moving area without electrons, surrounded by electrons. In reality, the hole is a lack of something, but by treating the lack of a negatively charged particle as the presence of a positively charged particle with certain special properties, we can vastly simplify certain challenges in understanding the behavior of matter on this level. For instance, the exchange of electrons and electron holes is crucial to harvesting energy in solar photovoltaic panels, electrons are excited and move around within the cell, in turn pushing around the no-electron area and, in a certain way of looking at it, swapping places with a “hole.” Trying to work with the dynamics of such a process is almost impossible looking only at electrons. But as a mixture of electron particles and electron hole quasiparticles, each with their own sets of behaviour, it makes much more sense. There are more quasiparticles than just electron holes, however. “Excitons” arise from stable association between electrons and holes. The researchers used their new collider to test the binding energy of excitons, how much energy it takes to pull an exciton apart. Excitons are interesting in part because they can transfer energy via their electron without transferring a net electric charge, which is washed out by the associated hole. Carbon nanotube “spasers” work by using surface plasmons. There are quasi-particles called surface plasmons that confine photon-like particles to the surface of a material, which could revolutionize computing by allowing processing at the speed of light. Understanding the dynamics of surface plasmons will be necessary to work past the current problems with cooling and power consumption in optical computing prototypes. They live on a list with many other quasiparticles, with names like magnons and dropletons, none of which are understood as well as we’d like. So, how do you slam an electron into the lack of an electron? The collider works by using femtosecond pulses of infrared light to create pairs of electrons and excitons in a small sample of test material (in this case tungsten diselenide), and a terahertz electric field accelerates them together at thousands of km/second. In just a few billionths of a second, the quasiparticle collider tears our sample apart and smashes it back together with enough force to create measurable amount of nuclear energy. Solar power could see rapid advancement with a better understanding of quasiparticle behaviour. The very concept of working with something that is, in reality, just an emergent property of the interactions of many other things, gets at the weirdness of modern quantum science. It shows how physicists have been at least somewhat reasonable to treat things like holes as real entities in the physical world, because that’s exactly how they behave. .It’s an exciting thing to have confirmed, as the researcher talk about wanting to move on from tungsten diselenide to graphene, a super-material that has already been used to transport surface plasmons in the past. The world’s most powerful particle colliders may be the machines that give us fundamental insight into the structure of the universe, but it could well be these more specialized laboratories that give rise to the inventions that shape the

a. present b. future c. colliders d. beams.

Q78.arXiv:1705.03895v1 [astro-ph.HE] 10 May 2017: Mon. Not. R. Astron. Soc.000, 1–12 (2017) 12 May 2017: Shock-powered light curves of luminous red novae as signatures of pre-dynamical mass loss in stellar mergers: Brian D. Metzger1, Ondˇrej Pejcha2 1 Columbia Astrophysics Laboratory, Columbia University, New York, NY, 10027, USA 2 Lyman Spitzer Jr. Fellow, Department of Astrophysical Sciences, Princeton University, Princeton, NJ, 08544, USA: ABSTRACT Luminous red novae (LRN) are a class of optical transients believed to originate from the mergers of binary stars, or “common envelope” events. Their light curves often show secondary maxima, which cannot be explained in the previous models of thermal energy diﬀusion or hydrogen recombination without invoking multiple independent shell ejections. We propose that double-peaked light curves are a natural consequence of a collision between dynamically-ejected fast shell and pre-existing equatorially-focused material, which was shed from the binary over many orbits preceding the dynamical event. The fast shell expands freely in the polar directions, powering the initial optical peak through cooling envelope emission. Radiative shocks from the collision in the equatorial plane power the secondary light curve peak on the radiative diﬀusion timescale of the deeper layers, similar to luminous Type IIn supernovae and some classical novae. Using a detailed 1D analytic model, informed by complementary 3D hydrodynamical simulations, we show that shock-powered emission can explain the observed range of peak timescales and luminosities of the secondary peaks in LRN for realistic variations in the binary parameters and fraction of the binary mass ejected. The dense shell created by the radiative shocks in the equatorial plane provides an ideal location for dust nucleation consistent with the inferred aspherical geometry of dust in LRN. For giant stars, the ejecta forms dust when the shock-powered luminosity is still high, which could explain the infrared transients recently discovered by Spitzer. Our results suggest that pre-dynamical mass loss is common if not ubiquitous in stellar mergers, providing insight into the instabilities responsible for driving the binary merger. Finally, although we focused on a simple mass loss history prior to the dynamical phase of the merger, in principle a more complex series of mass ejection events could occur if the common envelope evolution occurs in several stages (e.g. Ivanova et al. 2013). In such cases, more than two broad light curve peaks are possible, similar to the complex light curve structure observed in some Type IIn SNe. The bimodal picture of a fast dynamical explosion plowing into a slow steady wind adopted in this work is also almost certainly too simpliﬁed; the transition between these two phases will in reality be more,

a. gradual b. abnormal c. speedy d. sudden

Q79.arXiv:1705.04073v1 [cond-mat.str-el] 11 May 2017: Classical Spin Spirals in Frustrated Magnets from Free-Fermion Band Topology: Jan Attig and Simon Trebst Institute for Theoretical Physics, University of Cologne, 50937 Cologne, Germany (Dated: May 12, 2017) The formation of coplanar spin spirals is a common motif in the magnetic ordering of many frustrated magnets. For classical antiferromagnets, geometric frustration can lead to a massively degenerate ground state manifold of spirals whose propagation vectors can be described, depending on the lattice geometry, by points (triangular), lines (fcc), surfaces (frustrated diamond) or completely ﬂat bands (pyrochlore). Here we demonstrate an exact mathematical correspondence of these spiral manifolds of classical antiferromagnets with the Fermi surfaces of free-fermion band structures. We provide an explicit lattice construction relating the frustrated spin model to a corresponding free-fermion tight-binding model. Examples of this correspondence relate the 120◦ order of the triangular lattice antiferromagnet to the Dirac nodal structure of the honeycomb tight binding model or the spiral line manifold of the fcc antiferromagnet to the Dirac nodal line of the diamond tight-binding model. We discuss implications of topological band structures in the fermionic system to the corresponding classical spin system. An interesting aspect of the spin fermion correspondence is that it points a way to inferring the ground-state physics of a frustrated magnet (which might be hard to access) from the band topology of a free-fermion system at the Fermi energy (which might be readily available) and vice versa. In practice, the most intriguing example of such a transfer would have been to ﬁnd topological aspects of the fermion system reincarnate themselves in the spin system. While we have explored this idea in the context of edge states to no success, it remains to be seen whether it works in other instances such as the suggestion that the ground state of the triaxially strained triangular lattice antiferromagnet might exhibit topological features similar to the corresponding triaxially strained fermion model on the honeycomb lattice. The reverse direction – inferring features of the fermionic band structure from knowledge about the ground state of the corresponding spin model–has proved insightful in constructing simple fermion models that exhibit completely ﬂat bands at the Fermi energy as demonstrated for the extended honeycomb and diamond lattices. This might be a useful starting point for the further construction of fractional Chern insulators or other non-trivial states that are generated from an interaction induced splitting of such highly degenerate ﬂat

a. overlaps b. lattices c. spirals d. bands

Q80. arXiv:1705.04143v1 [physics.gen-ph]: Cosmological Acceleration from Scalar Field and Classical and Quantum Gravitational Waves (Inflation and Dark Energy) Leonid Marochnik, Physics Department, East-West Space Science Centre, University of Maryland, College Park, MD 20742. We show that on the average, homogeneous and isotropic scalar field and on the average homogeneous and isotropic ensembles of classical and quantum gravitational waves generate the de Sitter expansion of the empty (with no matter) space-time. At the start and by the end of its cosmological evolution the Universe is empty. The contemporary Universe is about 70% empty, so the effect of cosmological acceleration should be very noticeable. One can assume that it manifests itself as dark energy. At the start of the cosmological evolution, before the first matter was born, the Universe is also empty. The cosmological acceleration of such an empty space-time can manifests itself as inflation. To get the de Sitter accelerated expansion of the empty space-time under influence of scalar fields and classical and quantum gravitational waves, one needs to make a mandatory Wick rotation, i.e. one needs to make a transition to the Euclidean space of imaginary time. One can assume that the very existence of inflation and dark energy could be considered as a possible observable evidence of the fact that time by its nature could be a complex value which manifests itself precisely at the start and by the end of the evolution of the Universe, i.e. in those periods when the Universe is empty (or nearly empty). Quantum metric fluctuations in imaginary time (graviton-ghost instantons) form a macroscopic de Sitter state in real time as do GW and scalar field. This fact is supposed to be confirmed by observational data which could be the existing dark energy and inflation effects. As we see, usually Wick rotation is used in the quantum instanton theories. However, as was shown in Sections 2 and 3, Wick rotation leads to the same de Sitter expansion of empty space in classical cases too, and this means that a central role is played not by the quantum nature but the transition to imaginary time by Wick rotation. Recall that the integration along real time axis in earlier work, leading to divergent integrals should be replaced by integration along the imaginary time axis in leading to convergent integrals. In the case of virtual gravitons the situation is not so unambiguous. For instance, de Sitter solution can be obtained in real time (without Wick rotation) but price for that is a “materialization” of ghosts which are non-physical particles. This means that we operate in the plane of complex variable t (or η), i.e. we use time as a complex variable. Time as a complex variable is just a mathematical trick that leads to the desired result, or is there behind it certain new physics? The mathematical aspects of time as a complex quantity was extensively discussed in literature see G. Esposito, Int. Journal of Geometric Methods in Modern Physics, pp.1-59, 2005; arXiv: hepth/0504089v2.The best known attempt to ascribe physical meaning to the imaginary time was made by B.J. Hartle and Hawking, Phys. Rev, D28, 2960, 1983. Later, Hawking emphasized repeatedly in his books on popular science a possible reality of imaginary time. As is shown in this paper, the de Sitter accelerated expansion of the empty FLRW space under back-reaction of quantum metric fluctuations, classical gravitational waves and/or scalar field require a mandatory transition to the Euclidean space of imaginary time and then return to the Lorentzian space of real time. On the other hand, the de Sitter accelerated expansion of the empty space at the beginning and end of the evolution of the Universe is confirmed by observational data (dark energy and inflation). One can assume that the very existence of these two effects is the observable evidence to the fact that time by its nature could be a complex value in the empty space-time of the

a. Euclidean space b. universe c. world d. quantum metric.

Q81. arXiv:1705.07902v1 [astro-ph.GA] 22 May 2017: Testing General Relativity with stellar orbits around the supermassive black hole in our Galactic center. A. Hees et al, Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA and Spain (Dated: May 24, 2017): ABSTRACT: In this Letter, we demonstrate that short-period stars orbiting around the supermassive black hole in our Galactic Center can successfully be used to probe the gravitational theory in a strong regime. We use 19 years of observations of the two best measured short-period stars orbiting our Galactic Center to constrain a hypothetical ﬁfth force that arises in various scenarios motivated by the development of a uniﬁcation theory or in some models of dark matter and dark energy. No deviation from General Relativity is reported and the ﬁfth force strength is restricted to an upper 95% conﬁdence limit of |α| < 0.016 at a length scale of λ = 150 astronomical units. We also derive a 95% conﬁdence upper limit on a linear drift of the argument of periastron of the short-period star S0-2 of |˙ωS0-2| < 1.6×10⁻³ rad/yr, which can be used to constrain various gravitational and astrophysical theories. This analysis provides the ﬁrst fully self-consistent test of the gravitational theory using orbital dynamic in a strong gravitational regime, that of a supermassive black hole. A sensitivity analysis for future measurements is also presented. A speciﬁc theoretical model covered by the ﬁfth force framework is a massive graviton. In that context, we found a 90% conﬁdence limit λ > 5000 A.U. for α = 1, which can be interpreted as a lower limit on the graviton’s Compton wavelength λg > 7.5 × 10¹¹ km or, equivalently, as an upper bound on the graviton’s mass mg < 1.6×10⁻²¹ eV/c². In conclusion, we have used 19 years of observations of S0-2 and S0-38 reported earlier to constrain a hypothetical ﬁfth interaction around the SMBH in our Galactic Center. Our results are complementary to the ones obtained in the Solar System since they are obtained in a completely diﬀerent and unexplored strong ﬁeld regime. We have shown that future observations and especially the next generation of telescopes will improve our results substantially. In addition, we have derived a limit on a hypothetical advance of the periastron of the short-period star S0-2, a constraint that can be used to constrain various astrophysical and fundamental physics scenarios in the Galactic Center. This analysis shows that we are currently entering an era where astrometric and spectroscopic observations of short-period stars around Sgr A* can be used to probe

a. theoretical aspects b. Galaxy c. field regime d. fundamental physics

Q82. arXiv:1705.08017v1[gr-qc]: Mon, 22 May 2017 21:45:26 GMT: A tale of two dyons: G´erard Cl´ementa, Dmitri Gal’tsovb,c: Russia c Kazan Federal University, 420008 Kazan, Russia. Abstract: We present a one-parameter family of stationary, asymptotically ﬂat solutions of the Einstein Maxwell equations with only a mild singularity, which are endowed with mass, angular momentum, a dipole magnetic moment and a quadrupole electric moment. We brieﬂy analyze the structure of this solution, which we interpret as a system of two extreme co-rotating black holes with equal masses and electric charges, and opposite magnetic and gravimagnetic charges, held apart by an electrically charged, magnetized string which also acts as a Dirac-Misner string. This solution can be analytically continued beyond the horizons. The most economical maximal analytical extension contains two interior regions between an outer and an inner horizon (both degenerate), and beyond the inner horizons a third region extending to spacelike inﬁnity and containing a timelike ring singularity. Comparing with other known stationary solutions describing two-black hole systems, we think that this one has a minimal number of physically undesirable features and can be considered as “almost” physical. This surprising property is presumably related to the speciﬁc generating technique of [arXiv: gr-qc/9710109], which endows the static seed solution with rotation and charges, all depending on a single parameter. Applying this transformation to the general-γ ZV solution generically gives singular space-times with novel features, which may be interesting in view of recent discussions of alternatives to Kerr in astrophysical modelling. It is worth noting that our solution belongs to a subclass of the nine parameter family of solutions of the Einstein-Maxwell equations constructed in [Phys. Rev. D 62, 044048 (2000)], whose physical features are still

a. unexplored b.unknown c. indeterminate d. explored.

Q83. https://arxiv.org/abs/1707.03398: Astronomy & Astrophysics manuscript no. v854 c: ESO 2017July 13, 2017: Letter to the Editor: Unidentiﬁed emission features in the R Coronae Borealis star V854 Centauri L. C. Oostrum, B. B. Ochsendorf, L. Kaper1, and A. G. G. M. Tielens: e-mail: l.c.oostrum@uva.nl, The Netherlands. ABSTRACT: During its 2012 decline the R Coronae Borealis star (RCB) V854 Cen was spectroscopically monitored with X-shooter on the ESO Very Large Telescope. The obscured optical and near-infrared spectrum exhibits many narrow and several broad emission features, as previously observed. The envelope is spatially resolved along the slit and allows for a detailed study of the circumstellar material. In this Letter we report on the properties of a number of unidentiﬁed emission features (UFs), including the detection of a new one at λ8692Å. These UFs have been observed in the Red Rectangle, but their chemical and physical nature is still a mystery. The previously known UFs behave similarly in the Red Rectangle and V854 Cen, but are not detected in six other observed RCBs. Possibly the presence of some hydrogen is required for the formation of their carrier(s). The λ8692 UF is present in all RCBs. Its carrier is likely of a carbonaceous molecular nature, presumably diﬀerent from that of the other UFs. Only about a hundred RCBs are known in the Galaxy. V854 Cen is an RCB that is of particular interest because it is one of the few RCBs that include hydrogen lines in their spectra; It is the most hydrogenrich RCB. The broad features at 5800, 5827, 5854 and 6617 Å were ﬁrst recognized in V854 Cen by Rao & Lambert (1993b) during a deep decline (mV ∼ 15). The similarity between these features and the emission features in the RR was already noted. We expand upon this by considering the spatial and dynamical (i.e. radialvelocity)structure of these features in V854Cen. Noneof these bands are detected in any of the other observed RCBs.The spectra reveal the presence of abroad emission feature at 8692Å that has not been seen before in any RCB, nor in the RR. The behaviour of the λ8692 feature is diﬀerent for each RCB. In RT Nor and RZ Nor, the width of the feature does not change signiﬁcantly, while a narrowing with increasing distance is observed in the others. The position of the feature shifts in all objects. There is no clear pattern to this, in some objects only blueshift is observed, in others also redshift and/or no shift on one side of the star. As the RCBs have diﬀerent distances, different physical scales are probed, but we do not ﬁnd a correlation between the behaviour of this feature and the respective distances to the RCBs. The λ8692 feature may provide insight in the geometry of this dust in V854Cen, as it is the only UF that is detected clearly on both sides of the star. We are unable to identify a possible DIB counterpart for the λ8692 feature. The closest known DIB is located at 8648.3 Å (online catalogue1 and N.L.J. Cox, priv. comm.), which is too far oﬀ to be the likely absorption equivalent of the

                a.    λ5800        b.     λ8692      c.   λ6617        d. λ8648.3

Q84. arXiv:1707.03400v1 [astro-ph.SR] 11 Jul 2017: Solar Extreme UV radiation and quark nugget dark matter model: Ariel Zhitnitsky Department of Physics & Astronomy, University of British Columbia, Vancouver, B.C. V6T 1Z1, Canada: We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ωdark ∼ Ωvisible when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of matter which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter ΛQCD. We also present arguments suggesting that the transient brightening-like “nano-ﬂares” in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario. A variety of anomalous solar phenomena still defy conventional theoretical understanding. For example, the detailed physical processes that heat the outer atmosphere of the Sun to 106K remain a major open issue in astrophysics. The quark nugget model is conceptually similar, with the nuggets being composed of a high density colour superconducting (CS) phase. By the formation temperature Tform ~ 41 MeV at which the nuggets and antinuggets compete their formation, when all anti baryons get annihilated and only the baryons remain in the system. The main features of the observed nano-ﬂares are consistent with our identiﬁcation of nano-ﬂare events with the annihilation of the dark matter anti-nuggets. Tunguska-like events when no fragments or chemical traces have ever been recovered. We speculate that such unusual events might be the result of the collision of the anti-nugget with Earth. A very diﬀerent study of a number of correlations in the Sun and its planets strongly suggest a presence of “invisible matter”. It would be very interesting to see if the DM nuggets are capable to play the role of the
        a. Dark Matter b. Light-Matter c. Invisible Matter. d. Super-Matter

Q85. arXiv:1707.03852v1 [astro-ph.CO] Big Bang Nucleosynthesis with Stable 8Be and the Primordial Lithium Problem: Richard T. Scherrer Department of Astronomy, University of Illinois, Urbana, IL 61801 and and Department of Computer Science, University of Illinois, Urbana, IL 61801: Robert J. Scherrer Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235: ABSTRACT: A change in the fundamental constants of nature could stabilize 8Be against decay into two 4He nuclei. Coc et al. examined this eﬀect on big bang nucleosynthesis as a function of B8, the mass diﬀerence between two 4He nuclei and a single 8Be nucleus, and found no eﬀects for B8 ≤ 100 keV. Here we examine larger B8 and also allow for a variation in the rate for 4He + 4He −→ 8Be to determine the threshold for interesting eﬀects. We ﬁnd no change to standard big bang nucleosynthesis for B8 < 1 MeV. For B8 > ∼ 1 MeV and a suﬃciently large reaction rate, a signiﬁcant fraction of 4He is burned into 8Be, which ﬁssions back into 4He when B8 assumes its present-day value, leaving the primordial 4He abundance unchanged. However, this sequestration of 4He results in a decrease in the primordial 7Li abundance. Primordial abundances of 7Li consistent with observationally-inferred values can be obtained for reaction rates similar to those calculated for the present-day (unbound 8Be) case. Even for the largest binding energies and largest reaction rates examined here, only a small fraction of 8Be is burned into heavier elements, consistent with earlier studies. There is no change in the predicted deuterium abundance for any model we examined. Our results indicate that it is diﬃcult to produce signiﬁcant abundances of CNO elements in BBN even with MeV scale binding energies for 8Be. In that regard, the famous “mass gap” at A = 8 is misleading; the failure to produce heavier elements in the early universe is a result of the lower densities and shorter times for nuclear fusion than prevail in stars. This analysis ignores the possibility that, for large values of B8 and F0, the build-up of a large mass fraction of 8Be might allow the reaction 8Be + 8Be −→ 16O + γ to compete with reaction (9) as a mechanism for the production of the CNO elements, but that seems unlikely in view of the large Coulomb barrier. Of course, these results are also sensitive to the assumed rate for 8Be + 4He; a rate that diverges from that of K. Nomoto, F. K. Thielemann, and S. Miyaji, Astron. Astrophys. 149, 239 (1985), could alter our conclusions regarding the CNO elements. This work is admittedly speculative; our goal was to establish a threshold on the 8Be binding energy and the 4He + 4He reaction rate that would produce a reduction in the primordial lithium abundance. While the possibility of solving the lithium problem through a change in the constants of nature, including the binding energies of the light nuclei, is not new, the sequestration of 4He during BBN noted here represents a qualitatively mechanism which is
                     a. outstanding      b. affirmative     c. New       d. Novel

Q86. https://arxiv.org/abs/1707.04091: Spintronics: Maxwell-Dirac theory, charge and spin: S. C. Tiwari Department of Physics, Institute of Science, Banaras Hindu University, and Institute of Natural Philosophy, Varanasi 221005, India: The nature of spin current and the separation of charge current and spin current are two of the fundamental questions in spintronics. For this purpose the classical limit of the Maxwell-Dirac theory is investigated in the present contribution. Since the Dirac equation reduces to the Weyl equation for massless particles, a vortex solution is obtained for the Weyl equation and it is argued that mass has stochastic origin. The Weyl vortex is embedded in a Gaussian wavepacket to deﬁne physical vortex. Two-vortex internal structure of electron is developed in terms of Weyl and subquantum Weyl vortices characterized by hcross and f = e^2 / 2πc respectively. It is suggested that this model may ﬁnd application in spintronics with a new
                    a. perspective     b. Idea        c. thought   d. creation.

Q87. Schwarzschild-de Sitter spacetime: the role of Temperature in the emission of Hawking radiation: Thomas Pappas1 and Panagiota Kanti2 Division of Theoretical Physics, Department of Physics, University of Ioannina, Ioannina GR-45110, Greece. Abstract: We consider a Schwarzschild-de Sitter (SdS) black hole, and focus on the emission of massless scalar ﬁelds either minimally or non-minimally coupled to gravity. We use six diﬀerent temperatures, two black-hole and four eﬀective ones for the SdS spacetime, as the question of the proper temperature for such a background is still debated in the literature. We study their proﬁles under the variation of the cosmological constant, and derive the corresponding Hawking radiation spectra. We demonstrate that only few of these temperatures may support signiﬁcant emission of radiation. We ﬁnally compute the total emissivities for each temperature, and show that the non-minimal coupling constant of the scalar ﬁeld to gravity also aﬀects the relative magnitudes of the energy emission rates. The novel feature of our analysis is the use of six diﬀerent temperatures for the SdS background, as the question of the proper temperature for such a spacetime is still debated in the literature. We have thus considered the bare temperature, deﬁned in terms of the black-hole surface gravity, the normalised temperature, that takes into account the absence of an asymptotically-ﬂat limit, and four eﬀective temperatures deﬁned in terms of both the black-hole and cosmological horizon temperatures. We ﬁrst studied the proﬁles of the above temperatures as a function of the cosmological constant Λ, from a zero value up to its maximum, critical limit. We have found that the temperatures are split in two groups depending on their behaviour in these two asymptotic Λ-regimes. In the limit of zero cosmological constant, the aforementioned temperatures either reduce to the temperature of the Schwarzschild black hole or vanish; near the critical limit, they either assume a non-vanishing asymptotic value or reduce again to zero. Their diﬀerent proﬁles inevitably aﬀect the form of the energy emission rates for
            a. Hawking radiation. b. effective radiation c. black-hole d. SdS
Q88. arXiv:1707.05158 [physics.gen-ph]:General Physics (physics.gen-ph) Journal reference: Jour. of Physics (Conf.) Vol 845, 012030 (2017): Thu, 13 Jul 2017 18:06:34 GMT: A Generalized Spin Statistics Theorem: Paul O’Hara Istituto Universitario Sophia,Via San Vito, 28 - Loppiano, 50064 Figline e Incisa Valdarno (FI), Italy: E-mail: paul.ohara@iu-sophia.org: Abstract. In this article we generalize the spin statistics theorem and show that a state obeys Fermi-Dirac statistics if and only if the state is invariant under the action of SL(n, C). We also brieﬂy discuss the experimental evidence and how the theorem relates to spin entanglement.The origin of quantum statistics seems to have begun in 1920 when S.K. Bose sent a paper to Einstein seeking his help in getting it published. Einstein recommended it to Zeitschrift but later also published his own version in which the notion of indistinguishable photon states were introduced. a necessary and suﬃcient condition for the Pauli exclusion principle to be valid is the requirement that the quantum state of a system of n particles be invariant under the action of the SL(n,C) group. As we have already noted this requires the existence of spin singlet states, which means that spin entanglement is a necessary requirement to exhibit Fermi-Dirac statistics. Indeed, Fermi-Dirac statistics can be deﬁned as the statistics of n indistinguishable
                     a. triplet states   b. singlet states   c. particles    d. fields.
Q89. arXiv:1707.08568 [gr-qc]: AXION AS A COLD DARK MATTER CANDIDATE: PROOF TO FULLY NONLINEAR ORDER Hyerim Noh, Jai-chan Hwang, Chan-Gyung Park, Korea, Draft version, July 28, 2017. ABSTRACT We present a proof of the axion as a cold dark matter candidate to the fully nonlinear order perturbations based on Einstein’s gravity. We consider the axion as a coherently oscillating massive classical scalar ﬁeld without interaction. We present the fully nonlinear and exact, except for ignoring the transverse-trace free tensor-type perturbation, hydrodynamic equations for an axion ﬂuid in Einstein’s gravity. We show that the axion has the characteristic pressure and anisotropic stress, the latter starts to appear from the second-order perturbation. But these terms do not directly aﬀect the hydrodynamic equations in our axion treatment. Instead, what behaves as the eﬀective pressure term in relativistic hydrodynamic equations is the perturbed lapse function and the relativistic result coincides exactly with the one known in the previous non-relativistic studies. The eﬀective pressure term leads to a Jeans scale which is of the solar-system scale for conventional axion mass. As the fully nonlinear and relativistic hydrodynamic equations for an axion ﬂuid coincide exactly with the ones of a zero-pressure ﬂuid in the super-Jeans scale, we have proved the cold dark matter nature of such an axion in that scale. In this work we have shown that the axion as a massive coherently oscillating scalar ﬁeld behaves as nonrelativistic zero-pressure ﬂuid in the super-Jeans scale. The eﬀective pressure term of the axion ﬂuid is the same as the one known in the non-relativistic analysis. Here we have treated the axion as a massive scalar ﬁeld without any self-interaction. Interaction terms, if becomes important, may cause qualitatively different changes which are beyond the scope of this work. Although we presented our proof in a single axion ﬁeld case, the extension to realistic multi-component situations with additional presence of baryon and radiation, etc. is trivial; in the hydrodynamic case. In a zero-pressure ﬂuid, our Equations show that the pure Einstein’s gravity correction terms start to appear from the third order, and all the correction terms involve ϕ. The leading nonlinear power spectra of the density and velocity perturbations show that the pure Einstein’s gravity correction terms appearing in the third order are entirely negligible compared with the relativistic/Newtonian power spectra in all scales in the context of current concordance cosmology. Thus, in the zero-pressure medium (with the cosmological constant) the Newtonian analysis is quite reliable at least up to weakly nonlinear stages. In the super-Jeans scale, therefore, we have proved that the axion behaves as a CDM (zero-pressure ﬂuid) independently of whether the gravity is relativistic or Newtonian. In the relativistic case, Equations four of them presented are the fully nonlinear equations for an axion ﬂuid in the axion-comoving
a. gauge    b. fluid    c. radiation    d. cosmology

Q90. arXiv:1707.08675v1 [astro-ph.EP] 27 Jul 2017: PROSPECTS OF DYNAMICAL DETERMINATION OF GENERAL RELATIVITY PARAMETER β AND SOLAR QUADRUPOLE MOMENT J2 WITH ASTEROID RADAR ASTRONOMY: Ashok K. Verma, Jean-Luc Margot, and Adam H. Greenberg: University of California, Los Angeles, CA 90095, USA. Submitted to ApJ. ABSTRACT We evaluated the prospects of quantifying the parametrized post-Newtonian parameter β and solar quadrupole moment J2 with observations of near-Earth asteroids with large orbital precession rates (9 to 27 arcseconds/century). We considered existing optical and radar astrometry, as well as radar astrometry that can realistically be obtained with the Arecibo planetary radar in the next ﬁve years. Our sensitivity calculations relied on a traditional covariance analysis and Monte Carlo simulations. We found that independent estimates of β and J2 can be obtained with fractional precisions of 6×10^−4 and 3×10^−8, respectively. Because we assumed rather conservative observational uncertainties, as is the usual practice when reporting radar astrometry, it is likely that the actual precision will be closer to 2×10^−4 and 10^−8, respectively. A purely dynamical determination of solar oblateness with asteroid radar astronomy may therefore rival the helioseismology determination. A modest observing campaign requiring 50-60 hours of Arecibo telescope time over the next ﬁve years can provide about 20 range measurements of asteroids whose orbits exhibit large perihelion shift rates. The Arecibo Planetary Radar facility is required for these measurements because its sensitivity is ∼20 times better than that of other radar systems, allowing detection of asteroids that are not detectable elsewhere. The Arecibo measurements will complement existing optical and radar astrometry and enable joint orbital solutions with β and J2 as adjustable parameters. Independent, purely dynamical determinations of both parameters are important because they place bounds on theories of gravity and the interior structure the of Sun, respectively. Prospects of determination of GR parameter β with asteroid radar astronomy. Our simulation results likely under-estimated actual precision for two reasons. First, we did not attempt to simulate the impact of future optical astrometry nor improvements to the accuracy of star catalogs. Both of these eﬀects will inevitably improve the quality of the orbital determinations. Second, we assumed, based on historical evidence, that radar observers assign fairly conservative uncertainties to their measurements, which often underestimate the precision of the measurements by a factor of ∼3. As a result, we anticipate that the uncertainties of the ﬁnal estimates will be close to σβ ∼ 2×10^−4, and solar quadrupole moment to be σJ2
   a. 10    b. 20 c. 10^-8 d. 10^-10

Q91. https://arxiv.org/pdf/1707.08674.pdf, Physical basis for the electron spin and antisymmetry: A ﬁrst-principles explanation:A. M. Cetto, L. de la Pen˜a and A. Vald´es-Herna´ndez Instituto de F´ısica, Universidad Nacional Aut´onoma de M´exico: July 28, 2017: Abstract: We present a possible physical explanation for the origin of both the electron spin and the related antisymmetry of the wave function, in the framework of (nonrelativistic) quantum mechanics as provided by linear stochastic electrodynamics. A separate consideration of the coupling of the electron with circularly polarized modes of the electromagnetic vacuum, taken as a real ﬂuctuating ﬁeld, allows to disclose the spin angular momentum and the associated magnetic moment with a g-factor 2, and to establish the connection with the usual operator formalism. Further, in a bipartite system the electrons are shown to couple in antiphase to the same vacuum ﬁeld modes. This ﬁnding, encoded in the antisymmetry of the wave function, provides a physical rationale for the Pauli principle. The extension of our results to a multipartite system is brieﬂy discussed. The above analysis can be extended to a multielectron system, subject again to a common zpf, thanks to the fact that the chain rule discussed in Sect. 3 remains in force for an arbitrary product of spin phases. To determine the resulting state of the system one must consider the various possible conﬁgurations A,B,C, ---------of stationary states corresponding to the same total energy EA = EB =EC ------- Yet direct application of this procedure becomes rather cumbersome, as the degeneracy increases rapidly with the number of particles. A convenient approach is to consider ﬁrst any pair of electrons of the system, say those in states α, α′. By taking successively every possible pair, all relevant frequencies will be accounted for, and all the respective symmetries will thus be included. Since as a result no pair of electrons can be in the same (single-particle) state, the state of the entire system will be described by a totally antisymmetric, multiply entangled state vector built of diﬀerent bipartite single-particle states that carry the factor (−1)^2pσ = (−1)^p in front of each term, where p stands for the number of transpositions in the permutation needed to reach the corresponding exchanged state, starting from the initial

a. state b. form c. shade d. factor

Q92. https://arxiv.org/pdf/1707.08917.pdf: Analysis of wave-packet tunnelling with the method of Laplace transformation: Natascha Riahi ∗ University of Vienna, Faculty of Physics, Gravitational Physics Boltzmanng. 5, 1090 Vienna, Austria: Abstract: We use the method of Laplace transformation to determine the dynamics of a wave packet that passes a barrier by tunnelling. We investigate the transmitted wave packet and ﬁnd that it can be resolved into a sequence of subsequent wave packages. This result sheds new light on the Hartmann eﬀect for the tunnelling time. Our result for the tunnelling time is not an exact reproduction of Hartmann’s result which predicts an increasing tunnelling time with the thickness of the barrier before saturation takes place. According to our calculations contributions to the tunnelling times that are proportional to the thickness of the barrier could only come from higher order contributions in p−p0 to 38 that might yield a correction to smaller momenta. But for thicker barriers the conclusion of both calculations is that the tunnelling time for suﬃciently peaked wave packets is given by. This is as far interesting as the results were obtained by completely diﬀerent methods. Moreover we ensured in our calculations that the initial wave-packet is only located at the left side of the barrier which is not clearly guaranteed by Hartmann’s approach. So our result makes sure that the Hartmann time is not an arti-fact of the stationary phase approximation or some relic of the parts of the initial wave-packet that were at the right hand side of the barrier from the beginning. We also found out that the approximate solution within a ﬁnite barrier diﬀers from the solution within the potential step only by a time-independent factor which also indicates that important dynamical properties are independent of the thickness of the barrier. It would be especially interesting if this is also true for more general tunnelling processes as the tunnelling out of a potential well that could model radioactive decay or tunnelling out of atoms as provided by the atto-clock experiment. Moreover an application of the method of Laplace transformation to relativistic wave equations would yield a picture of the reﬂection and tunnelling processes in the relativistic

a. spin b. case c. jump d. horizon

Q93. arXiv:1708.00041v1 [astro-ph.GA] 31 Jul 2017: Rediscovering our Galaxy Proceedings IAU Symposium No. 334, 2017 C. Chiappini, I. Minchev, E. Starkenburg & M. Valentini, eds. c 2017 International Astronomical Union. ABSTRACT: New insights on the origin of multiple stellar populations in globular clusters. Jaeyeon Kim and Young-Wook Lee Center for Galaxy Evolution Research & Department of Astronomy, Yonsei University, Seoul, Korea email: jaeyeonkim93@gmail.com, ywlee2@yonsei.ac.kr. Abstract. In order to investigate the origin of multiple stellar populations in the halo and bulge of the Milky Way, we have constructed chemical evolution models for the low-mass proto-Galactic subsystems such as globular clusters (GCs). Unlike previous studies, we assume that supernova blast waves undergo blowout without expelling the pre-enriched gas, while relatively slow winds of massive stars (WMS), together with the winds and ejecta from low and intermediate mass asymptotic-giant-branch stars (AGBs), are all locally retained in these less massive systems. We ﬁnd that the observed Na-O anti-correlations in metal-poor GCs can be reproduced, when multiple episodes of starbursts are allowed to continue in these subsystems. Speciﬁc star formation history (SFH) with decreasing time intervals between the stellar generations, however, is required to obtain this result, which is in good agreement with the parameters obtained from our stellar evolution models for the horizontal-branch. The “mass budget problem” is also much alleviated by our models without ad-hoc assumptions on star formation eﬃciency (SFE) and initial mass function (IMF). We also applied these models to investigate the origin of super-helium-rich red clump stars in the metal-rich bulge as recently suggested by Lee et al. (2015). We ﬁnd that chemical enrichments by the WMS can naturally reproduce the required helium enhancement (∆Y/∆Z = 6) for the second generation stars. Disruption of proto-GCs in a hierarchical merging paradigm would have provided helium enhanced stars to the bulge
   a. scope b. periods c. jumps    d. field
Q94.arXiv:1708.00173v1 [cond-mat.mes-hall] 1 Aug 2017: Phonon Eigenspectrum-Based Formulation of the Atomistic Green’s Function Method: Sridhar Sadasivam∗1, Umesh V. Waghmare2, and Timothy S. Fisher†1 1School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907 2Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientiﬁc Research, Jakkur, Bangalore 560064 Abstract: While the atomistic Green’s function (AGF) method has the potential to compute spectrally resolved phonon transport across interfaces, most prior formulations of the AGF method provide only the total phonon trans mission function that includes contributions from all phonon branches or channels. In this work, we present a formulation of the conventional AGF technique in terms of phonon eigenspectra that provides a natural decomposition of the total transmission function into contributions from various phonon modes. The method involves the use of Dyson and Lippmann-Schwinger equations to determine surface Green’s functions from the phonon eigenspectrum of the bulk, and establishes a direct connection between the transmission function and the bulk phonon spectra of the materials forming the interface. We elucidate our formulation of the AGF technique through its application to a microscopic picture of phonon mode conversion at Si-Ge interfaces with atomic intermixing. Intermixing of atoms near the interface is shown to increase the phase space available for phonon mode conversion and to enhance thermal interface conductance at moderate levels of atomic mixing. The eigenspectrum-based AGF (EAGF) method should be useful in determination of microscopic mechanisms of phonon scattering and identiﬁcation of the speciﬁc modes that dominate thermal transport across an interface. We demonstrated the proposed technique through analysis of thermal transport on Si-Ge interfaces with varying levels of intermixing between atoms. Our results reveal that interfacial intermixing relaxes the condition on conservation of transverse momentum and allows for increased degrees of freedom for elastic transfer of energy between bulk Si and bulk Ge phonon modes. The increased phase space for elastic scattering results in a higher transmission function in some phonon frequency ranges and leads to an increase in interfacial thermal conductance for intermixed interfaces in comparison to ideal or smooth interfaces. The example studied in this paper demonstrates the usefulness of the proposed extension to conventional AGF by providing new insights into the microscopic mechanisms of interfacial phonon scattering. More broadly, the present approach can provide mode-resolved transport as inputs to multiscale models such as the Boltzmann transport equation for studying heat transport at mesoscopic length
a. arcs    b. deviations    c. scales d. dimensions
Q95. :1708.00228v1 [cond-mat.mes-hall] 1 Aug 2017: Valley spin lifetimes reaching 100 ns in monolayer MoSe2 at room temperature: M. Ersfeld,1 F. Volmer,1 R. de Winter,1 C. Stampfer,1,2 and B. Beschoten1 1, 2nd Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany 2Peter Gru¨nberg Institute (PGI-9), Forschungszentrum Ju¨lich, 52425 Ju¨lich, Germany (Dated: August 2, 2017): ABSTRACT: We present time-resolved Kerr-rotation measurements on a monolayer of MoSe2 revealing spin lifetimes up to 100 ns at room temperature.This extraordinary long-lived spin signal only weakly depends on temperature between 60 K and 300 K. At lower temperatures, it gets masked by an additional spin signal with signiﬁcantly larger amplitude but shorter spin lifetimes reaching 8 ns. The latter spin signal exhibits a Kerr resonance which coincides with the photoluminescence spectrum from neutral and charged excitons showing that the spin dynamics at low temperatures are dominated by excitonic eﬀects. In contrast, the long-lived spin signal at higher temperatures shows no resonance in the energy regime of the excitons. The absence of such resonance combined with the long spin lifetimes at room temperature is expected if the spin dynamics at elevated temperatures are not dominated by excitonic eﬀects but by a polarization of resident holes, which is protected even at room temperature due to the large spin splitting in the valence bands of transition metal dichalcogenides. In summary, the spin dynamics in the MoSe2 monolayer are governed by excitonic eﬀects up to a temperature of 40 K. Once this exciton-related Kerr rotation signal gets diminished at higher temperatures, an additional spin signal becomes prominent with a lifetime up to 100 ns even at room temperature. As these long-lived spin states seem to be robust against temperature and do not exhibit obvious connection to the excitons in PL, it is indicative that they originate from a valley polarization of resident hole carriers in the valence bands. The required spin-ﬂip scattering mechanism for a transfer of spin information from an exciton polarization to resident charge carriers might be provided by localized defect states. From a technological point of view, the observed spin lifetimes in the ns-range are important for possible gate-induced spin manipulation in the GHz-regime and subsequent spin transfer to e.g. graphene with its high spin transport lengths in order to build room temperature functional spintronic devices. In summary, the spin dynamics in the MoSe2 monolayer are governed by excitonic eﬀects up to a temperature of 40 K. Once this exciton-related Kerr rotation signal gets diminished at higher temperatures, an additional spin signal becomes prominent with a lifetime up to 100 ns even at room temperature. As these long-lived spin states seem to be robust against temperature and do not exhibit obvious connection to the excitons in PL, it is indicative that they originate from a valley polarization of resident hole carriers in the valence bands. The required spin-ﬂip scattering mechanism for a transfer of spin information from an exciton polarization to resident charge carriers might be provided by localized defect states. From a technological point of view, the observed spin lifetimes in the ns-range are important for possible gate-induced spin manipulation in the GHz-regime and subsequent spin transfer to e.g. graphene with its high spin transport lengths in order to build room temperature functional spintronic
a. models b.devices    c. carriers d. polarisations

Q96. https://arxiv.org/ftp/arxiv/papers/1708/1708.00250.pdf: Contact morphology and revisited photocurrent dynamics in monolayer MoS2: Eric Parzinger, Martin Hetzl, Ursula Wurstbauer and Alexander W. Holleitner, Germany. ABSTRACT: Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) have emerged as promising materials for electronic, optoelectronic, and valleytronic applications. Recent work suggests drastic changes of the band gap and exciton binding energies of photo-excited TMDs with ultrafast non-radiative relaxation processes effectively heating the crystal lattice. Such phenomena have not been considered in the context of optoelectronic devices yet. We resolve corresponding ultrafast photoconductance dynamics within monolayer MoS2 and demonstrate that a bolometric contribution dominates the overall photoconductance. We further reveal that a focused laser illumination, as is used in many standard optoelectronic measurements of MoS2, modifies and anneals the morphology of metal contacts. We show that a junction evolves with lateral built-in electric fields, although Raman- and photoluminescence spectra indicate no significant changes such as a crystal phase transition. We highlight how such optimized devices can drive ultrafast electromagnetic signals in on-chip high-frequency and THz circuits.

a. Hz circuits b. BHz circuits c. CHz circuits. d. THz circuits

Q97.https://arxiv.org/ftp/arxiv/papers/1707/1707.09262.pdf: Flexible Hall Sensors Based on Graphene: Zhenxing Wang,* Mehrdad Shaygan, Martin Otto, Daniel Schall, Daniel Neumaier, Advanced Microelectronic Center Aachen (AMICA), AMO GmbH, Otto-Blumenthal-Straße 25, 52074 Aachen, Germany, Email: wang@amo.de. Abstract : The excellent electronic and mechanical properties of graphene provide a perfect basis for high performance flexible electronic and sensor devices. Here, we present the fabrication and characterization of flexible graphene based Hall sensors. The Hall sensors are fabricated on 50µm thick flexible Kapton foil using large scale graphene grown by chemical vapor deposition technique on copper foil. Voltage and current normalized sensitivities of up to 0.096 V/VT and 79 V/AT were measured, respectively. These values are comparable to the sensitivity of rigid silicon based Hall sensors and are the highest values reported so far for any flexible Hall sensor devices. The sensitivity of the Hall sensor shows no degradation after being bent to a minimum radius of 4 mm, which corresponds to a tensile strain of 0.6%, and after 1,000 bending cycles to a radius of 5 mm. In summary, flexible Hall sensors based on graphene are realized, which show a voltage and current normalized sensitivity of up to 0.096 V/VT and 79 V/AT, respectively, comparable to rigid silicon based Hall sensors and significantly outperforming all flexible Hall sensors so far by more than one order of magnitude. A further increase of the sensitivity of graphene based Hall sensors is still possible using either a flexible encapsulation or ultimately high quality graphene encapsulated in hBN. The graphene Hall sensors are only 50 µm thick and the sensitivity is stable for bending radius down to 4 mm and for 1,000 bending cycles to a radius of 5 mm. Therefore graphene based Hall sensors will enable upcoming applications in the fields such as wearable electronics or electronic skin,
          a. devices    b. sensors    c. bio-medicine    d. portable electronic.
Q98. arXiv:1708.00498v1 [physics.plasm-ph] 1 Aug 2017: Energetic-particle-modiﬁed global Alfv´en eigenmodes J.B. Lestz,1,2, a) E.V. Belova,2 and N.N. Gorelenkov2 1)Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08543, USA 2)Princeton Plasma Physics Lab, Princeton, NJ 08543, USA.(Dated: 3 August 2017) ABSTRACT: Fully self-consistent hybrid MHD/particle simulations reveal strong energetic particle modiﬁcations to subcyclotron global Alfv´en eigenmodes (GAE) in low-aspect ratio, NSTX-like conditions. Key parameters deﬁning the fast ion distribution function – the normalized injection velocity v0/vA and central pitch – are varied in order to study their inﬂuence on the characteristics of the excited modes. It is found that the frequency of the most unstable mode changes signiﬁcantly and continuously with beam parameters, depending most substantially on v0/vA. This unexpected result is present for both co- and counter-propagating GAEs, which are driven by Doppler-shifted cyclotron resonances. Large changes in frequency without clear corresponding changes in mode structure could indicate the existence of a new energetic particle mode, referred to here as an energetic-particle-modiﬁed GAE (EP-GAE). Additional simulations conducted for a ﬁxed MHD equilibrium demonstrate that the GAE frequency shift cannot be explained by the equilibrium changes due to energetic particle eﬀects.There have been previous studies showing an MHD mode’s eigenfrequency changing in proportion to energetic particle velocity. One is the so-called “resonant toroidicity-induced Alfv´en eigenmode” (RTAE), which is characterized by the mode frequency decreasing in order to remain in resonance with fast particles as TEP/Ti decreases45. Cheng et al. remark that this trend can lead the RTAE to have a frequency much below the characteristic TAE gap frequency that it is associated with, just as the GAEs in these simulation results can be signiﬁcantly displaced from the minimum in the Alfv´en
              a. distracts    b. continuum     c. jumps    d. Waves

Q99. arXiv:1708.00661v1 [gr-qc] 2 Aug 2017: Universality of tunnelling particles in Hawking radiation Harold Erbin∗1 and Vincent Lahoche†2 1Arnold Sommerfeld Center for Theoretical Physics, Ludwig–Maximilians–Universität München, Theresienstraße 37, 80333 München, Germany 2Labri, Université de Bordeaux, Umr 5800, 33405 Talence, France. 3rd August 2017. Abstract The complex path (or Hamilton–Jacobi) approach to Hawking radiation corresponds to the intuitive picture of particles tunnelling through the horizon and forming a thermal radiation. This method computes the tunnelling rate of a given particle from its equation of motion and equates it to the Boltzmann distribution of the radiation from which the Hawking temperature is identiﬁed. In agreement with the original derivation by Hawking and the other approaches, it has been checked case by case that the temperature is indeed universal for a number of backgrounds and the tunnelling of particles from spin 0 to 1 (and in some cases with spin 3/2 and 2). In this letter we give a general proof that the temperature is indeed equal for all (massless and massive) particles with spin from 0 to 2 on an arbitrary background (limited to be Einstein for spin greater than 1) in any number of dimensions. Moreover we propose a general argument to extend this result to any spin greater than 2. In his seminal paper; Hawking proved that black holes emit a thermal radiation at a temperature T due to quantum mechanical eﬀects. The intuitive picture of this radiation is the following: pairs of virtual particles created near a black hole horizon through vacuum ﬂuctuations become real once one of them cross the horizon while the other extracts energy from the black hole. This idea has lead to two diﬀerent approaches of the Hawking radiation: the complex path (or Hamilton–Jacobi) method due to Shankaranarayanan– Srinivasan–Padmanabhan, and the null geodesic method or Parikh– Wilczek method. Both methods are not restricted to black hole radiation but can also be applied for any black hole with a thermal horizon for other background which can be thermal, such as the Rindler or de Sitter spaces. Moreover they can also be used to deﬁne the Hawking temperature in situations where the traditional methods are not
a. defined b. formulated    c. oriented d. explicit

Q100.The Indian Science Congress Association 105th Physics Session to be held Osmania University on Jan 3-7, 2018. Molecular N-TiO2 for Solar Visible-Active Particles; ABSTRACT: Unlike the Valence-Conduction model of N-TiO2 studied and reported by N. T. Nolan et al, in 2011. I have formulated a molecular approach to analyse the Solar Visible-Active Particles. The molecular N-TiO2 exhibits a contrasting data for Ti-N bond length R as either 2.129Ȧ or as 1.58Ȧ. Present description differs from standard approach. The Mass of Titanium used as XM:47.867, Mass of O used as YM:15.999, and Mass of N used as N:14.007. With A=50Ȧ the particle size, CF and SF as the cosine and sine values of angle 110 degrees, especially the value of the parameter BR1 drastically changes between the mentioned two bond lengths, with BR1=4.0*(A*YM*SF)^2*((D+R)^2/XM)/(R^2) with D=(A*CF-S) with S=(A*CF*(XM+N)+R*N)/(D1^2) where D1=sqrt(XM+2*YM+N)=9.689 yields BR1 as 293711.9750 and 533284.3054 respectively for the mentioned two cases R=2.129Ȧ and R=1.58Ȧ.The molecular N-TiO2 exhibits a contrasting data for Ti-N bond length as either 2.129Ȧ or as 1.58Ȧ. Especially several parameters drastically changed between these two bond lengths. Also I use A= 50Ȧ, as the particle size. Mass of Ti used XM=47.867, Mass of O used as YM=15.999, and Mass of N used as N=14.007. Angle between the molecular Ti-O bonds is 110deg bond angle. ALP=0.017453293*110=1.92, SF = sin(ALP/2.0) = 0.82, CF = cos(ALP/2.0) = 0.57. The value of the parameter BR1=4.0*(A*YM*SF)^2*((D+R)^2/XM)/(R^2) with D=(A*CF-S) with S=(A*CF*(XM+N)+R*N)/(D1^2) where D1=sqrt(XM+2*YM+N)=9.6888. drastically changes for 2.129Ȧ and 1.58Ȧ, between these two bond lengths with BR1=293711.9750 and BR1=533284.3054,
   a. judiciously b. elaborately    c. respectively d. incidentally
Q101.The Indian Science Congress Association 105th Session to be held at Osmania University on Jan 3-7, 2018. ISC 2018, January 3 to 7, MATHEMATICS SESSION A NEW FORMULATION OF A TWELFTH ORDER GROUP EQUATION TO DESCRIBE PARTICLES AND THEIR THREE MASSES. Professor Dr. Kotcherlakota L. N. ABSTRACT: The new equations of twelfth order to describe the particle is enunciated. It involves in twelfth order. Positive mass analysis by twelfth order group matrix as [M1-X1, X2, X3, X4; M2-X5, X6, X7, X8; M3-X9] . We have chosen the sub-group {A, B, C, D, E, F, G, H, I, J, K, L}, in terms of X1, X2, X3, X4, X5, X6, X7, X8, X9 which happens to be a subgroup of a bigger Group G (S3). [kotcherlakota_l_n@hotmail.com]. The extensive analysis, reveals the present equation with unsymmetrical matrix form and scaling, yields real solution. The three mass terms are very distinct and, unlike the Dirac equation, reveals new mathematics involving only positive mass terms. The present work describes the third order matrix description of the particle with masses M1=0.4375c; M2=3.0875c; M3=-1.7625c with the scaling factor c chosen as Unity. The mass terms obtained here may perhaps be considered alike the neutrino masses but with essential difference that I have obtained them as most general fundamental particles with a twelfth order equation. Hence the comparison with the neutrino masses may be an adventurous thought. The present work is very unique in the sense it attempts at solving a twelfth order equation for recovery of the three fundamental eigenvalues. It is a step beyond the work of Asan Danmanik who, using the advantages of the experimental data of squared mass diﬀerences, obtained neutrino masses in normal hierarchy i.e. m1 = 0.028188eV, m2 = 0.029488eV, and m3 = 0.057676eV. These are negative masses while in my work I deal with masses that are,
   a. redundant    b. explicit    c. oscillatory   d. positive
Q102. arXiv:1708.01052v1: Quantum Physics (quant-ph); Mathematical Physics (math-ph): Resonant-tunnelling in discrete-time quantum walk: Kaname Matsue, Leo Matsuoka, Osamu Ogurisu, Etsuo Segawa: Japan: August 3, 2017: Abstract: We show that discrete-time quantum walks on the line, Z, behave as “the quantum tunnelling.” In particular, quantum walkers can tunnel through a double-well with the transmission probability 1 under a mild condition. This is a property of quantum walks which cannot be seen on classical random walks, and is diﬀerent from both linear spreadings and localizations. Finally, we mention that this resonant-tunnelling phenomenon of QW can be realized in experiment. The operators will be implemented by half wave plates and polarizing beam splitters, and the steady injection of the quantum walker will be implemented by laser. The conceptual design of ring-resonator named Quantum Walk Resonator will be discussed in the forthcoming paper. The quantum walk (QW) is a quantum version of the classical random walk. Their primitive forms of the discrete-time quantum walks on Z can be seen in Feynman’s checker board. It is mathematically shown that this quantum walk has a completely diﬀerent limiting behaviour from classical random walks, which is a typical example showing a diﬃculty of intuitive description of quantum walks’ behavior. Relations between QW and its background quantum mechanics (QM) are very interesting, too. In this article, we consider the quantum tunnelling, which is one of the most famous quantum eﬀects and has well-developed since the early period of QM; this eﬀect shows that a quantum particle can tunnel through a barrier that it classically could not surmount. In particular, the resonant-tunnelling is very
   a. impressive b. thought provoking c. innovative d. rudimentary

Q103. arxiv.org.1708.00804v1: Band Structure of Two-dimensional Dirac Semi-metal from Cyclotron Resonance: A. M. Shuvaev, V. Dziom, N. N. Mikhailov, Z. D. Kvon, Y. Shao, D. N. Basov, and A. Pimenov: ABSTRACT: Knowing the band structure of materials is one of the prerequisites to understand their properties. Therefore, especially in the last decades, angle-resolved photo-emission spectroscopy (ARPES) has become a highly demanded experimental tool to investigate the band structure. However, especially in thin ﬁlm materials with a layered structure and several capping layers, access to the electronic structure by ARPES is limited. Therefore, several alternative methods to obtain the required information have been suggested. Here, we directly invert the results by cyclotron resonance experiments to obtain the band structure of a two-dimensional (2D) material. This procedure is applied to the mercury telluride quantum well with critical thickness which is characterized by a 2D electron gas with linear dispersion relations. The Dirac-like band structure in this material could be mapped both on the electron and on the hole side of the band diagram. In this material, purely linear dispersion of the hole-like carriers is in contrast to detectable quadratic corrections for the electrons. In conclusion, we directly obtained the band structure of a two-dimensional Dirac semi metal from the doping dependence of the cyclotron resonance. We observe a linear Dirac-like dispersion on the hole side of the band structure and detectable quadratic corrections for the electrons. This procedure to obtain the band structure is especially useful for thin ﬁlms where protective layers impede such standard techniques as angular resolved photoemission spectroscopy (ARPES).
a. ARES    b. electron & hole side c. Mercury-Telluride d. band structure.

Q104. arXiv:1708.01007v1 [physics.data-an] 3 Aug: Practical Statistics: L. Lyons Blackett Lab., Imperial College, London, UK and Particle Physics, Oxford, UK. Abstract: Accelerators and detectors are expensive, both in terms of money and human effort. It is thus important to invest effort in performing a good statistical analysis of the data, in order to extract the best information from it. This series of lectures deals with practical aspects of statistical issues that arise in typical High Energy Physics analyses. Systematic uncertainties can also arise in the measuring process. The quantities we measure may be shifted from the true values. For example, our measuring device may be miscalibrated, or the number of events we count may be not only from the desired signal, but also from various background sources. Such effects would bias our result, and we should correct for them, for example by performing some calibration measurement. The systematic uncertainty arises from the remaining uncertainty in our corrections. Systematics can cause a similar shift in a repeated series of experiments, and so, in contrast to statistical uncertainties, they may not be detectable by looking for a spread in the results. For example consider a pendulum experiment designed to measure the acceleration due to gravity g at sea level in a given location: g = 4π^2L/τ^2 where L is the length of the pendulum, τ = T/N is its period, and T is the time for N oscillations. The uncertainties we have mentioned so far are the statistical ones on L and T. There may also be systematic uncertainties on these variables. Unfortunately there are further possible systematics not associated with the measured quantities, and which thus require more careful consideration. For example, the derivation of for g assumes that: – our pendulum is simple i.e. the string is massless, and has a massive bob of inﬁnitesimal size; – the support of the pendulum is rigid; – the oscillations are of very small amplitude (so that sinθ ≈ θ); and – they are undamped. Note that although N involves counting the number of swings, we do not have to allow for Poisson ﬂuctuations, since there are no random ﬂuctuations involved. None of these will be exact in practice, and so corrections must be estimated for them. The uncertainties in these corrections are systematics. Furthermore, there may be theoretical uncertainties. For example, we may want the value of g at sea level, but the measurements were performed on top of a mountain. We thus need to apply a correction, which depends on our elevation and on the local geology. There might be two or more different theoretical correction factors, and again this will contribute a systematic uncertainty.
a. reliability    b. uncertainty c. explanation d. contribution

Q105. https://arxiv.org/pdf/1708.00959.pdf: RELATIVISTIC GAS DRAG ON DUST GRAINS AND IMPLICATIONS: Thiem Hoang Korea Astronomy and Space Science Institute, Daejeon 34055, Korea; thiemhoang@kasi.re.kr and Korea University of Science and Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Korea: ABSTRACT: We study the drag force on dust grains moving at relativistic velocities through interstellar gas and explore its application. First, we derive a new analytical formula of the drag force at high energies and ﬁnd that it is signiﬁcantly reduced compared to the classical model. Second, we employ the obtained drag force to calculate the terminal velocities of interstellar grains accelerated by strong radiation sources such as supernovae and active galactic nuclei (AGNs). We ﬁnd that grains can be accelerated to relativistic velocities by very luminous AGNs. We then quantify the deceleration of relativistic spacecraft proposed by the Breakthrough Stars hot initiative due to gas drag on a relativistic lightsail. We ﬁnd that the spacecraft’s slowing down is negligible because of the suppression of gas drag at relativistic velocities, suggesting that the light-sail may be open for communication during its journey to α Centauri without causing a considerable delay. Finally, we show that the damage to relativistic thin light-sails by interstellar dust is a minor eﬀect. Using the new drag formula, we calculated the terminal velocities of grains accelerated by radiation pressure from SNe and AGNs. We found that grains can be accelerated to relativistic velocities by very strong radiation sources, such as Seyfert galaxies and Quasars. Such relativistic dust grains were once referred to explain ultrahigh energy cosmic rays, but it is shown in (Hoang et al. 2015) that relativistic grains would be destroyed rapidly in the ISM by Coulomb explosions. Finally, we showed that the slowing down of relativistic light-sails of the type envisioned by Breakthrough Stars hot due to interstellar gas drag is negligible thanks to the suppression of gas drag at relativistic velocities. Thus, the light-sail can be open for communication and navigation during its journey to α Centauri without resulting in a considerable delay. We also evaluated the damage of thin relativistic light-sails by interstellar dust, which appears to be a minor
   a. affect    b. change c. influence d. effect

Q106. https://arxiv.org/ftp/arxiv/papers/1708/1708.01238.pdf: Hysteresis in the transfer characteristics of MoS2 transistors Antonio Di Bartolomeo, Luca Genovese, Filippo Giubileo, Laura Iemmo, Giuseppe Luongo, Tobias Foller and Marika Schleberger,email:adibartolomeo@unisa.it : Abstract: We investigate the origin of the hysteresis observed in the transfer characteristics of back-gated fieldeffect transistors with an exfoliated MoS2 channel. We find that the hysteresis is strongly enhanced by increasing either gate voltage, pressure, temperature or light intensity. Our measurements reveal a steplike behavior of the hysteresis around room temperature, which we explain as water-facilitated charge trapping at the MoS2/SiO2 interface. We conclude that intrinsic defects in MoS2, such as S vacancies, which result in effective positive charge trapping, play an important role, besides H2O and O2adsorbates on the unpassivated device surface. We show that the bistability associated to the hysteresis can be exploited in memory devices. We studied hysteresis effects in back-gated MoS2 transistors as a function of electrical stress and various environment conditions such as pressure, temperature and light. we fabricate back-gated, exfoliated-MoS2 transistors and we investigate the effects of gate voltage stress and environmental conditions. Our study confirms that hysteresis is enhanced by Owe fabricate back-gated, exfoliated-MoS2 transistors and we investigate the effects of gate voltage stress and environmental conditions. Our study confirms that hysteresis is enhanced by O2 or H2O molecules adsorbed on the device surface and can be quenched by reducing the pressure or the temperature. Our experimental findings suggest that hysteresis is strongly related to water, which facilitates charge transfer and trapping, and is favored when thermally-generated or photogenerated minority carriers (holes) become available in the n-type MoS2 transistor. We suggest that intrinsic defects such as S vacancies or other interfacial states, which result in effective positive charge trapping, are an important cause of hysteresis. or H2O molecules adsorbed on the device surface and can be quenched by reducing the pressure or the temperature. Our experimental findings suggest that hysteresis is strongly related to water, which facilitates charge transfer and trapping, and is favored when thermally-generated or photogenerated minority carriers (holes) become available in the n-type MoS2 transistor. We suggest that intrinsic defects such as S vacancies or other interfacial states, which result in effective positive charge trapping, are an important cause of hysteresis. We concluded that a contribution to the hysteresis comes from S vacancies in the MoS2 layer that behave as effective positive-charge trap centers. We pointed out that charge transfer from/to such centers is facilitated by the polarization of water molecules. We also showed that O2 adsorption or exfoliation residues on MoS2 in-passivated surface enhance the hysteresis. The same effect is caused by temperature and light, which both increase the availability of photo- or thermal-generated minority carriers and enable additional trapping processes. Finally, we pointed out that the hysteresis can be exploited in memory devices or in
a. photo-sensors b. photo-objects c. photodetectors d. photo-diodes
Q107.https://arxiv.org/ftp/arxiv/papers/1708/1708.00323.pdf: Optical forces through the effective refractive index: JANDERSON R. RODRIGUES, AND VILSON R. ALMEIDA, jrr@ita.br: ABSTRACT: The energy-based methods as the Dispersion Relation (DR) and Response Theory of Optical Forces (RTOF) have been largely applied to obtain the optical forces in the nano-opto-mechanical devices, in contrast to the Maxwell Stress Tensor (MST). In this work, we apply first principles to show explicitly why these methods must agree with the MST formalism in linear lossless systems. We apply the RTOF multi-port, to show that the optical force expression on these devices can be extended to analyse multiple light sources, broadband sources, and multimode devices, with multiple degrees of freedom. We also show that the DR method, when expressed as a function of the derivative of the effective index performed at a fixed wave vector, may be misinterpreted and lead to overestimated results. we apply first principles to explicitly show why these energy-based methods must agree with the MST formalism. We analyse a typical nano-optomechanical device to show that the DR method, expressed in terms of the effective index with derivative performed at a fixed wave vector, may overestimate the optical force if the correct transformations are not used, thus disagreeing with the MST. We also use the RTOF theory to extend the correct expression to more general cases. In conclusion, we have applied first principles to show that the energy-based methods, such as DR and RTOF, must agree with the MST formalism in linear lossless systems. By using the RTOF method, we have also shown that the derivative of the effective index expression could be easily extended to more complex cases. Finally, we have used a literature example to show that the DR method, when expressed in terms of the derivative of the effective index, has to be used with caution, since a common misinterpretation can overestimate the optical force by a factor of
a. ng/neff    b. neff/ng    c. ng*neff d. neff+ng

Q108. arXiv:1708.00507v1 [gr-qc] 1 Aug 2017: Straight spinning cosmic strings in Brans-Dickegravity: S. Mittmann dos Santos, Brazil & J. M. Hoﬀ da Silva and J. L. Cindra, Brazil: It is presented an exact solution of straight spinning cosmic strings in Brans-Dicke theory of gravitation: The possibility of the existence of closed timelike curves around these cosmic strings is analyzed. Furthermore, the stability about the formation of the topological defect discussed here is checked. It is shown the existence of a suitable choice for the integration constants in which closed timelike curves are not allowed. The Brans-Dicke (BD) gravitation is the simplest scalar-tensorial theory in which the gravitational phenomena is described by a tensorial and a scalar ﬁeld. The dynamical equations, for the scalar and tensorial ﬁelds, have a dimensionless parameter, ω, controlling the departure from usual General Relativity (GR). It is usually understood that cosmic strings are topological defects, which arose from as spontaneous symmetry breaking occurred in some phase transition of the early Universe, and therefore can provide some information about most fundamental theories. Spinning cosmic strings are a particular class of approximately one-dimensional topological defects that have an angular velocity around the longitudinal axis of symmetry and whose dynamics is associated to the Gödel’s solutions. Spinning strings were largely studied in GR, and its solutions conﬁrm the existence of closed timelike curves(CTC’s)in at least part of the resulting spacetime around the defect. The point to be emphasized in those previous works is that the CTC’s are generally generated by non-physical sources. As the formation of spinning cosmic strings would have occurred in the early Universe, an approach with BD gravitation, it can bring some additional information not yet obtained within GR. Spinning cosmic strings were investigated in the context of BD gravity, but the obtained solutions are overly particular, since the performed analysis takes advantage of a scalar ﬁeld particular shape. The closer the unit is this parameter, the greater is the diﬀerence between the description of phenomena given by GR and the BD theory. Current solar system experiments sets ω > 4000. We ﬁnalize stressing that the complete spacetime analysis, taking into account the interior solution, is under investigation and shall make explicit the hole performed by the BD parameter. To the best of our hope, a procedure akin to the one presented in B. Jensen and H. Soleng, Phys. Rev. D 45, 3528 (1992), working out the ballpoint pen model, along with appropriate junction conditions may lead to a solution free of naked
a. scalar fields   b. jumps c. systems   d. singularities

Q109. arXiv:1707.08724v1 [nlin.CD] 27 Jul 2017: NONLINEAR PROCESSES: ISSN 2071-0186. Ukr. J. Phys. ZZZZ. Vol. YY, No. X 1: V. GRYTSAY Bogolyubov Institute for Theoretical Physics, Nat. Acad. of Sci. of Ukraine (14b, Metrolohichna Str., Kyiv 03680, Ukraine) STRUCTURAL INSTABILITY OF A BIOCHEMICAL PROCESSPACS 05.45.-a, 05.45.Pq, 05.65.+b: ABSTRACT: By the example of a mathematical model of a biochemical process, the structural instability of dynamical systems is studied by calculating the full spectrum of Lyapunov indices with the use of the generalized Benettin algorithm. For the reliability of the results obtained, the higher Lyapunov index determined with the orthogonalization of perturbation vectors by the Gram–Schmidt method is compared with that determined with the over determination of only the norm of a perturbation vector. Specific features of these methods and the comparison of their efficiencies for a multidimensional phase space are presented. A scenario of the formation of strange attractors at a change of the dissipation parameter is studied. The main regularities and the mechanism of formation of a deterministic chaos due to the appearance of a fold or a funnel, which leads to the uncertainty of the evolution of a biosystem, are determined. Even a slight deviation of the initial data influences essentially the evolution of the trajectory, namely the deterministic chaos is created. Such a chaos characterizes the appearance of a random nonpredictable behavior of a system controlled by deterministic laws. We note that, in real biosystems, the fluctuations are permanently present and, in unstable modes, create chaotic states. Thus, the given mathematical model adequately describes stable autoperiodic modes, as well as unstable chaotic ones. Conclusions Due to the successful development of an algorithm of calculations of the full spectrum of Lyapunov indices on an ordinary personal computer for a multidimenIsional phase space not bounded by the number of variables, we manage to reliably calculate these indices. This allows one to extend the possibilities to forecast the dynamics of complicated systems. By the example of a mathematical model of biosystems, we have found two different scenarios of the formation of the modes of a strange attractor: the creation of a fold or a funnel, where the formation of a deterministic chaos is realized. The self-organization of the phase flow of a strange attractor occurs under the action of two mutually competitive processes: the exponential extension (of one of the components, in the given case) and the dissipative contraction of the whole phase space. Any fluctuation which has appeared there causes the nonpredictability of the evolution of the system on the
   a. chaos b.whole c. scenario d. attractor.
Q110."https://arxiv.org/abs/1708.00542v1: Traveling wave solutions for wave equations with exponential nonlinearities: S C Mancas, email: mancass@erau.edu. H C Rosu and M. P´erez-Maldonado,maximino.perez@ipicyt.edu.mx. ABSTRACT: We use a simple method which leads to the quadrature involved in obtaining the traveling wave solutions of wave equations with one and two exponential nonlinearities. When the constant term in the integrand is zero, implicit solutions in terms of hypergeometric functions are obtained while when that term is nonzero we give all the basic traveling wave solutions based on a detailed study of the corresponding elliptic equations of several well-known particular cases with important applications in physics. we have used a very simple method to obtain the quadrature of the general form of wave equations with two exponential nonlinearities whose particular cases correspond to celebrated equations in mathematical physics, such as Liouville, Tzitz´eica and its variants, sine-Gordon, and sinh-Gordon equations. All the basic soliton, periodic and Weierstrass solutions of these equations are obtained consistently in the traveling variable by a thorough analysis of the elliptic equation. Particular implicit solutions in terms of a generic hypergeometric function are also obtained through a direct integration. Some of these solutions, such as the Weierstrass solutions of the Tzitz´eica class of equations and the amplitude Jacobi solutions of the sine/sinh-Gordon equations cannot be obtained by other methods in the literature, for example the well-known tanh method, although they can also be obtained via the integral bifurcation method. Of course, for more complicated multiple-soliton (multi-phase soliton) solutions, one should use Darboux and B¨acklund
a. transformations b. steps c. operators d. equations
Q111. https://arxiv.org/abs/1708.01627: MNRAS 000, 1–11 (2017) 8 August 2017 "Probing the formation history of the nuclear star cluster at the Galactic Centre with millisecond pulsars" F. Abbate, A. Mastrobuono-Battisti, M. Colpi1, A. Possenti, A. C. Sippel and M. Dotti, Italy, ABSTRACT The origin of the Nuclear Star Cluster in the centre of our Galaxy is still unknown. One possibility is that it formed after the disruption of stellar clusters that spiralled into the Galactic Centre due to dynamical friction. We trace the formation of the Nuclear Star Cluster around the central black hole, using state-of-the-art N-body simulations, and follow the dynamics of the neutron stars born in the clusters. We then estimate the number of Millisecond Pulsars (MSPs) that are released in the Nuclear Star Cluster, during its formation. The assembly and tidal dismemberment of globular clusters lead to a population of MSPs distributed over a radius of about 20 pc, with a peak near 3 pc. No clustering is found on the sub-parsec scale. We simulate the detectability of this population with future radio telescopes like the MeerKAT radio telescope and SKA1, and ﬁnd that about of order ten MSPs can be observed over this large volume, with a paucity of MSPs within the central parsec. This helps discriminating this scenario from the in-situ formation model for the Nuclear Star Cluster that would predict an over abundance of MSPs closer to the black hole. We then discuss the potential contribution of our MSP population to the gamma-ray excess at the Galactic Centre. In order to check for the observability of the population of MSPs, the results of our cluster-in-spiral scenario need to be projected along a realistic line of sight. We choose to project along the line of sight that maximises the rotation of the NSC in order to reproduce the observed rotation. The projected distribution maintains the same distribution as is observed in Figure 4 but the peak moves to 2 pc. We divide the central parsecs in bins of width equal to the beam of the telescope, and count the number of radio-bright MSPs in each bin. The width of the beam – which will be obtained from the combination of the voltages collected at the various antennas of the arrays by using a beamforming procedure, is assumed to match the diﬀraction limited resolving power that implies a width of 8” which in turn corresponds to 0.32 pc at the distance of the Galactic Centre (assumed to be 7.86 kpc Boehle et al. 2016). The map of the intrinsic distribution of the MSPs is displayed, using a bin size equal to the beam width of the telescope. In this work we considered the cluster-inspiral scenario for the formation of the NSC at the Galactic Centre, based on the simulations described by Perets & Mastrobuono-Battisti (2014) and Tsatsi et al. (2017). We showed that this scenario predicts the existence of a population of MSPs resulting from the in-spiral and dismemberment of globular clusters hosting recycled neutron stars. The neutron star population has been inferred from a synthesis model by Sippel & Hurley (2013) that accounts for stellar evolution and mass segregation. The key ﬁnding is that MSPs are distributed over the entire NSC with no signiﬁcant clustering within the central
a. NSC    b. sec     c. parsec    d. MSPs
Q112. arXiv:1708.01788v1 [astro-ph.H] 5 August 2017: "Neutrino scattering in supernovae and spin correlations of a unitary gas"; Zidu Lin and C. J. Horowitz, 1Center for Exploration of Energy and Matter and Department of Physics, Indiana University, Bloomington, IN 47408, USA (Dated: August 8, 2017): ABSTRACT: Core collapse supernova simulations can be sensitive to neutrino interactions near the neutrino-sphere. This is the surface of last scattering. We model the neutrino-sphere region as a warm unitary gas of neutrons. A unitary gas is a low density system of particles with large scattering lengths. We calculate modiﬁcations to neutrino scattering cross sections because of spin and density correlations in the unitary gas. These correlations can be studied in laboratory cold atom experiments. We ﬁnd signiﬁcant reductions in cross sections, compared to free space interactions, even at relatively low densities. These reductions could reduce the delay time from core bounce to successful explosion in multidimensional supernova simulations. In conclusions, core collapse supernova simulations can be sensitive to neutrino interactions near the neutrino-sphere. In this paper we model the neutrino-sphere region as a warm unitary gas of neutrons. Using the virial expansion to fourth order we calculate modiﬁcations to neutrino scattering cross sections because of spin correlations in the unitary gas. These spin correlations can be studied in laboratory cold atom experiments. We ﬁnd signiﬁcant reductions in cross sections, even at relatively low densities. These reductions could reduce the delay time from core bounce to successful explosion in multidimensional supernova
a. simulations b. modifications c. changes d. reductions
Q113. arXiv:1708.02381v1 [math.NT]: A MAGNETIC DOUBLE INTEGRAL: DAVID BROADHURST AND WADIM ZUDILIN: To the memory of Jonathan Borwein (1951–2016): ABSTRACT: In a recent study of how the output voltage of a Hall plate is aﬀected by the shape of the plate and the size of its contacts, Ausserlechner has come up with a remarkable double integral that can be viewed as a generalization of the classical elliptic “AGM” integral. Here we discuss transformation properties of the integral, which were experimentally observed by Ausserlechner, as well as its analytical and arithmetic features including connections with modular forms.In a recent study of how the output voltage of a Hall plate is aﬀected by the shape of the plate and the size of its contacts, U. Ausserlechner has come up with the double integral. With trigonometrical coeﬃcients C(m,n) that are non-zero if and only if m belongs to a sequence S of integers, beginning with 1,5,13. Further numerical work revealed that this sequence continues as follows: 1, 5, 13, 17, 25, 29, 37, 41, 53, 61, 65, 73, 85, 89, 97, ..., from which we inferred that S is the sequence of positive integers divisible only by primes congruent to 1 modulo
a. 8         b. 16         c. 256      d. 4
Q114.arxiv.org.1708.02462v1:[gr-qc]; 9 August 2017: "Reviving The Shear-Free Perfect Fluid Conjecture In General Relativity":E-mail: skhmuz002@myuct.ac.za, skhmuz002@gmail.com, sikhome@unisa.ac.za,E-mail:peter.dunsby@uct.ac.za. ABSTRACT; Employing a Mathematica symbolic computer algebra package called xTensor, we present (1 + 3) - covariant special case proofs of the shear-free conjecture for perfect ﬂuids in General Relativity. We ﬁrst present the case where the pressure is constant and then where the acceleration is parallel to the vorticity vector, which were ﬁrst presented in their covariant form by Senovilla et. al. We then provide a covariant proof for the case where the acceleration and vorticity vectors are orthogonal, which leads to the existence of a Killing vector along the vorticity. This Killing vector satisﬁes the new constraint equations resulting from the vanishing of the shear, and it is shown that for the conjecture to be true, this Killing vector must have a vanishing spatially projected directional covariant derivative along the velocity vector ﬁeld, which in turn implies the existence of another basic vector ﬁeld along the direction of the vorticity for the theorem to hold. Finally, we show that in general if the acceleration is non-zero, there exist a basic vector ﬁeld parallel to the acceleration for the conjecture to be true. We have shown that if the acceleration is not zero, the exist a basic vector Va along it for the conjecture to be true. The shear-free perfect ﬂuid conjecture is true if and only if either the vorticity or the acceleration vectors are aligned with some hypersurface basic vectors. We deduce that the general proof of the shear-free perfect ﬂuid conjecture will encompass the analysis based on basic variables of the theory. For the upcoming work, we will use the techniques developed in this work to extend this analysis to the case of f(R) gravity. In particular we will examine the stability of the GR version of this theorem by considering theories of the form f(R) = R+δ , where δ << 1 as our strating
a. solution    b. point     c. conjecture   d. gravity
Q115. https://arxiv.org/pdf/1708.02730.pdf: August 10, 2017: Self-gravity Correction to the Chandrasekhar Limiting Mass of White Dwarfs: Kolkata, Bengaluru, Belur, West Bengal, India: Abstract: While computing the Fermi degeneracy pressure of electrons in a white dwarf star within the framework of hydrostatic equilibrium, we depart from the extant practice of treating the electrons as a free fermion gas, by including the eﬀect of the star’s self-gravity as an eﬀective gravitational potential. By the star’s self gravity, we mean the gravitational ﬁeld due to the star itself, resulting from the mass of its constituent atoms, the mass of the atom being eﬀectively the mass of the proton. Modifying the free particle Hamiltonian with this eﬀective potential, we employ ﬁrst order quantum mechanical perturbation theory to compute the degeneracy pressure, in order to study the eﬀect of inclusion of this self-gravity of the star on the Chandrasekhar limiting mass. The ﬁnal eﬀect is found to be non-trivial, but perhaps a shade too small to alter any major observational result. The expression of the ﬁrst two factors with ﬁrst term in the last factor in parenthesis is the original limiting mass a’ la Chandrasekhar, while the second term is our leading correction arising from self-gravity of the star producing an eﬀective gravitational potential inside the star. Clearly, this dimensionless correction term is a ratio of the mass of the electron to that of the proton, i.e., of the order of 10^−4, and hence substantially smaller compared to the original contribution. This is as may have been expected, and in a sense justiﬁes the neglect of the physical eﬀect discussed here, in the incipient analysis. However, the eﬀect is not so small as to be completely ignorable, especially if future observational studies require more precise results than what is available from the incipient analysis. From our calculations, we conclude that The eﬀect of a background gravitational potential on the electrons inside a White Dwarf is physical and produces a change in the mass-limit, the change being of the order of 10^−4. This change will also aﬀect the absolute luminosity of Type-Ia Supernovae as calculated from the Mass Limit. Since Type-Ia Supernovae act as Standard candles, our correction might have a signiﬁcant eﬀect in the measured value of the cosmological
   a. Mass Limit   b. parameters   c. luminosity d. candles
Q116. General Relativity and Quantum Cosmology (gr-qc); Quantum Physics (quant-ph): "Are Dark Energy and Dark Matter Different Aspects of the Same Physical Process?" R. E. Kastner, S. Kauffman: rkastner@umd.edu: ABSTRACT: It is suggested that the apparently disparate cosmological phenomena attributed to so-called 'dark matter' and 'dark energy' arise from the same fundamental physical process: the emergence, from the quantum level, of space-time itself. This creation of space-time results in metric expansion around mass points in addition to the usual curvature due to stress-energy sources of the gravitational field. A recent modification of Einstein's theory of general relativity by Chadwick, Hodgkinson, and McDonald incorporating space-time expansion around mass points, which accounts well for the observed galactic rotation curves, is adduced in support of the proposal. Recent observational evidence corroborates a prediction of the model that the apparent amount of 'dark matter' increases with the age of the universe. In addition, the proposal leads to the same result for the small but non-vanishing cosmological constant, related to 'dark energy, as that of the causet model of Sorkin et al. We have shown that a specific mechanism of space-time emergence from the quantum level leads to the space-time expansion quantitatively described in the theory of Chadwick, Hodgkinson, and McDonald (2013), which correctly predicts observed galaxy rotation data attribute to ‘dark matter.’ In addition, we have shown that the same mechanism yield a discrete space-time characterized by Poissonian uncertainties, similar to that proposed by Sorkin et al, which results in the necessary value of Λ to account for the ‘dark energy’ phenomenon, according to current observational data. In this model, we may understand ‘dark energy’ as a property arising from each element of space-time,as Sorkin says, “just by virtue of its existence” since a finite quantity of action is required in order for it to exist.The situationhas recently progressed significantly Chadwick, Hodgkinson, and McDonald (2013) have proposed modification of Einstein’s general relativity based on the principle that (idealized) point masses give rise not only to the usual space-time curvature, but also to space-time expansion. For a particular value of the parameter governing how rapidly space expands, they find their theory perfectly fits the galatic rotation data. This possible relation of dark energy and matter is intriguing, as it would unify apparently disparate and yet equally unexpected cosmological phenomena. If an expansion of space-time around mass points can account for the excess rotation of the outskirts of galaxies (i.e.,“dark matter”), and if this expansion is related to dark energy as outlined herein, we gain explanator parsimony as well as evidence for a fascinating connection of space-time with the explanatory parsimony as well as evidence for a fascinating connection of space-time with the quantum level. The latter could aid efforts to find a theory of quantum
   a. speculation b. thought c. rule d. gravity

Q117. Nature (2017) doi:10.1038/nature23655 Received 20 March 2017 Accepted 21 July 2017 Published online 09 August 2017: ABSTRACT: Quantum key distribution (QKD) uses individual light quanta in quantum superposition states to guarantee unconditional communication security between distant parties. In practice, the achievable distance for QKD has been limited to a few hundred kilometres, owing to the channel loss of fibres or terrestrial free space that exponentially reduced the photon rate. Satellite-based QKD promises to establish a global-scale quantum network by exploiting the negligible photon loss and decoherence in the empty out space. Here we develop and launch a low-Earth-orbit satellite to implement decoy-state QKD with over kHz key rate from the satellite to ground over a distance of up to 1,200 km, which is up to 20 orders of magnitudes more efficient than that expected using an optical fibre (with 0.2 dB/km loss) of the same length. The establishment of a reliable and efficient space-to-ground link for faithful quantum state transmission paves the way to global-scale quantum networks. The achievement based on experiments conducted with the world's first quantum satellite, Quantum Experiments at Space Scale (QUESS), was published in the journal Nature on Thursday. The communication distance between the satellite and the ground station varies from 645 km to 1,200 km, and the quantum key transmission rate from satellite to ground is up to 20 orders of magnitude more efficient than that expected using an optical fibre of the same length. Satellite-based quantum key distribution can be linked to metropolitan quantum networks where fibres are sufficient and convenient to connect numerous users within a city over 100 km. We can thus envision a space-ground integrated quantum network, enabling quantum cryptography – most likely the first commercial application of quantum information – useful at a global scale." The establishment of a reliable and efficient space-to-ground link for faithful quantum state transmission paves the way to global-scale quantum
   a. thresholds b. links c. networks d. connections.

Q118. arXiv:1708.07499v1 [astro-ph.GA] 24 Aug 2017: MNRAS000, 1–13 (0000): 25 August 2017:Relative distribution of cosmic rays and magnetic ﬁelds: Amit Seta, Anvar Shukurov, Toby S. Wood Paul J. Bushby and Andrew P. Snodin, NE1 7RU, UK, and Thailand: ABSTRACT Synchrotron radiation from cosmic rays is a key observational probe of the galactic magnetic ﬁeld. Interpreting synchrotron emission data requires knowledge of the cosmic ray number density, which is often assumed to be in energy equipartition (or otherwise tightly correlated) with the magnetic ﬁeld energy. However, there is no compelling observational or theoretical reason to expect such tight correlation to hold across all scales. We use test particle simulations, tracing the propagation of charged particles (protons) through a random magnetic ﬁeld, to study the cosmic ray distribution at scales comparable to the correlation scale of the turbulent ﬂow in the interstellar medium('100pcinspiralgalaxies).In these simulations, we ﬁnd that there is no spatial correlation between the cosmic ray number density and the magnetic ﬁeld energy density. In fact, their distributions are approximately statistically independent. We ﬁnd that low-energy cosmic rays can become trapped between magnetic mirrors, whose location depends more on the structure of the ﬁeld lines than on the ﬁeld strength. Test particle simulations are constrained by the need to resolve the Larmor radius and period of the particle gyration. For this reason, it is not practical to model those particles of energies of order GeV that contribute most to the energy density of cosmic rays if the magnetic ﬁeld structure is to be resolved in full. For example, the Larmor radius of a 5GeV proton in a 5µG ISM magnetic ﬁeld is108 times smaller than100pc, the typical scale of the magnetic ﬁeld. Our conclusions are based on an extrapolation of the results obtained for particles of effectively much larger energies. Then modelling of cosmic ray propagation at lower energies requires a ﬂuid model based on a variant of the diffusion-advection equation but with the diffusion tensor that allows for the non-trivial structure of the
   a. magnetic field b. diffusion tensor c. Larmor radius d. cosmic rays

ANS: Q1a. Q2c. Q3d. Q4b. Q5b. Q6d. Q7a. Q8c. Q9b. Q10b. Q11a. Q12c. Q13d. Q14.b. Q15d. Q16d. Q17b. Q18a. Q19c. Q20a. Q21b. Q22d. Q23a. Q24d. Q25b. Q26d. Q27a. Q28b. Q29a. Q30.b. Q31c. Q32d. Q33a. Q34.c. Q35.b. Q36a. Q37b. Q38d. Q39a. Q40b. Q41a. Q42b. Q43c. Q44a. Q45c. Q46b. Q47c. Q48a. Q49a. Q50d. Q51c. Q52a. Q53c. Q54b. Q55a. Q56c. Q57b. Q58a. Q59c. Q60a. Q61c. Q62c. Q63a. Q64c. Q65b. Q66d. Q67b. Q68a. Q69d. Q70b. Q71a. Q72b. Q73d. Q74c. Q75a. Q76c. Q77b. Q78a. Q79d. Q80b. Q81d. Q82a. Q83b. Q84d. Q85c. Q86a. Q87a. Q88b. Q89b. Q90c. Q91a. Q92b. Q93d. Q94c. Q95b. Q96d. Q97c. Q98b. Q99a. Q100c. Q101d. Q102a. Q103b. Q104b. Q105d. Q106c. Q107a. Q108d. Q109b, Q110a. Q111c. Q112a. Q113d. Q114b. Q115b. Q116a. Q117c. Q118a.
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with respects to Mrs. Peramma Rangadhama Rao.

TRU_SCIENCE & TRU_TECHNOLOGY

Friday, September 8, 2017

TRUWIZ 118; TRU Vol.2017, Issue No.9, Dt. 9 September 2017 in Memory of Prof. K. R. Rao D.Sc.(Madras) D.Sc.(London)

a. Type I b. type II c. magnetic field d. spectrum

a. Zircons b. Gravitational Fields c. Supercontinent d. Rocks of 3.5Ga

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