TRUWIZ 122b: September 09, 2021:

 September 09, 2021: 

     TRUWIZ 122b            

(see also truwiz122a)

trusciencetrutechnology@blogspot.com

Volume 2021, Dated: 09 September 2021 

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

In Memory of

Late Professor Kotcherlakota Rangadhama Rao

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

(Birth on 09 September 1899 Early Morning, Berhampur

Demise on 20 June 1972 at 9 h 09 m 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.

at Narasimha Ashra, Official Colony, Maharanipeta.P.O, Visakhapatnam 530002]

TRUWIZ-122b

Q62. arXiv:2103.02759 [quant-ph][Submitted on 3 Mar 2021]: Wed, 3 Mar 2021 23:46:32 UTC(4,825 KB): Operating a passive on-chip superconducting circulator: device control and quasiparticle effects. by Dat Thanh Le, Clemens Muller, Rohit Navarathna, Arkady Fedorov, T. M. Stace. :ABSTRACT: Microwave circulators play an important role in quantum technology based on superconducting circuits. The conventional circulator design, which employs ferrite materials, is bulky and involves strong magnetic fields, rendering it unsuitable for integration on superconducting chips. One promising design for an on-chip superconducting circulator is based on a passive Josephson-junction ring. In this paper, we consider two operational issues for such a device: circuit tuning and the effects of quasiparticle tunneling. We compute the scattering matrix using adiabatic elimination and derive the parameter constraints to achieve optimal circulation. We then numerically optimize the circulator performance over the full set of external control parameters, including gate voltages and flux bias, to demonstrate that this multi-dimensional optimization converges quickly to find optimal working points. We also consider the possibility of quasiparticle tunneling in the circulator ring and how it affects signal circulation. Our results form the basis for practical operation of a passive on-chip superconducting circulator made from a ring of Josephson                                 

                         a. junctions   b. chips.   c. coverages   d. possibility.

Q63. arXiv:2103.03093 [quant-ph]: [Submitted on 4 Mar 2021]: Thu, 4 Mar 2021 15:20:05 UTC (30 KB): How does the Planck scale affect qubits?Matthew J. Lake. :ABSTRACT: Gedanken experiments in quantum gravity motivate generalised uncertainty relations (GURs) implying deviations from the standard quantum statistics close to the Planck scale. These deviations have been extensively investigated for the non-spin part of the wave function but existing models tacitly assume that spin states remain unaffected by the quantisation of the background in which the quantum matter propagates. Here, we explore a new model of nonlocal geometry in which the Planck-scale smearing of classical points generates GURs for angular momentum. These, in turn, imply an analogous generalisation of the spin uncertainty relations. The new relations correspond to a novel representation of {\rm SU(2)} that acts nontrivially on both subspaces of the composite state describing matter-geometry interactions. For single particles each spin matrix has four independent eigenvectors, corresponding to two 2-fold degenerate eigenvalues ±(ℏ+β)/2, where β is a small correction to the effective Planck's constant. These represent the spin states of a quantum particle immersed in a quantum background geometry and the correction by β emerges as a direct result of the interaction terms. In addition to the canonical qubits states, $\ket{0} = \ket{\uparrow}$ and $\ket{1} = \ket{\downarrow}$, there exist two new eigenstates in which the spin of the particle becomes entangled with the spin sector of the fluctuating spacetime. We explore ways to empirically distinguish the resulting `geometric' qubits, $\ket{0'}$ and $\ket{1'}$, from their canonical 

                           a. partners     b. coordinates    c. counterparts    d. conjugates.

Q64. arXiv:2103.03347 [astro-ph.EP]:[Submitted on 4 Mar 2021]:Thu, 4 Mar 2021 21:58:39 UTC (1,226 KB): Broadband Imaging of Meteor Radio Afterglows. S. S. Varghese, J. Dowell, K. S. Obenberger, G. B. Taylor, J. Malins. :ABSTRACT: We present observations of 86 meteor radio afterglows (MRAs) using the new broadband imager at the Long Wavelength Array Sevilleta (LWA-SV) station. The MRAs were detected using the all-sky images with a bandwidth up to 20 MHz. We fit the spectra with both a power law and a log-normal function. When fit with a power law, the spectra varied from flat to steep and the derived spectral index distribution from the fit peaked at -1.65. When fit with a log-normal function, the spectra exhibits turnovers at frequencies between 30-40 MHz, and appear to be a better functional fit to the spectra. We compared the spectral parameters from the two fitting methods with the physical properties of MRAs. We observe a weak correlation between the log-normal turnover frequency and the altitude of MRAs. However, the spectral indices from the power law fit do not show any strong correlations with the physical properties of 

                                  a. MBAs   b. MRAs   c. DRAs     d. PRAs.  

Q65. arXiv:2103.03950 [astro-ph.SR]:[Submitted on 5 Mar 2021]: Fri, 5 Mar 2021 21:31:03 UTC (2,776 KB): Warm millimetre dust in protoplanetary discs near massive stars. T. J. Haworth. :ABSTRACT: Dust plays a key role in the formation of planets and its emission also provides one of our most accessible views of protoplanetary discs. If set by radiative equilibrium with the central star, the temperature of dust in the disc plateaus at around 10−20K in the outer regions. However sufficiently nearby massive stars can heat the outer disc to substantially higher temperatures. In this paper we study the radiative equilibrium temperature of discs in the presence of massive external sources and gauge the effect that it has on millimetre dust mass estimates. Since millimetre grains are not entrained in any wind we focus on geometrically simple 2D-axisymmetric disc models using radiative transfer calculations with both the host star and an external source. Recent surveys have searched for evidence of massive stars influencing disc evolution using disc properties as a function of projected separation. In assuming a disc temperature of 20K for a disc a distance D from a strong radiation source, disc masses are overestimated by a factor that scales with D−1/2 interior to the separation that external heating becomes important. This could significantly alter dust mass estimates of discs in close proximity to θ1C in the Orion Nebular Cluster. We also make an initial assessment of the effect upon snow lines. Within a parsec of an O star like θ1C, a CO snow line no longer exists, though the water snow line is virtually unaffected except for very close separations of ≤

                           a.  0.005pc       b.  0.001pc        c.  0.006pc       d. 0.01pc.

Q66. arXiv:2103.04165 [astro-ph.HE]: [Submitted on 6 Mar 2021]: Sat, 6 Mar 2021 18:07:40 UTC (249 KB): Repeating Fast Radio Bursts from Collapse of Strange Star Crust. Jin-Jun Geng, Bing Li, Yong-Feng Huang. :ABSTRACT: In this work, we suggest that the intriguing repeating fast radio bursts (FRBs) are produced by the intermittent fractional collapses of strange star (SS) crust induced by refilling of accretion materials from its low-mass companion. Coherent radio emissions are released along the open field lines of the magnetosphere at a distance of roughly 100 times that of SS radius. Its periodic/sporadic/clustered temporal behaviors could be well understood in our scenario. Especially, the periodicity is attributed to the modulation of accretion rate through the disk instabilities (e.g., thermal-viscous instability). To account for a ∼16-day periodicity of the repeating FRB source 180916.J0158+65, a Shakura-Sunyaev disk with a viscosity parameter of α≃0.004 and an accretion rate of ≃3×10^16~g~s−1 in the low state is invoked. Monitoring the face-on low-mass X-ray binaries is strongly encouraged for future repeating FRB searches. Our scenario, if favored by future observations, will serve as indirect evidence for the strange quark matter 

                            a. gauge.    b. suggestion     c. hypothesis    d. scenario.

Q67. arXiv:2103.04241 [astro-ph.CO]:[Submitted on 7 Mar 2021]: Sun, 7 Mar 2021 02:56:21 UTC (1,283 KB): The Anomalous 21-cm Absorption at High Redshifts. Fulvio Melia. :ABSTRACTS: The EDGES collaboration has reported the detection of a global 21-cm signal with a plateau centered at 76 MHz (i.e., redshift 17.2), with an amplitude of 500^(+200)_(-500) mK. This anomalous measurement does not comport with standard cosmology, which can only accommodate an amplitude < 230 mK. Nevertheless, the line profile's redshift range (15 < z < 20) suggests a possible link to Pop III star formation and an implied evolution out of the `dark ages.' Given this tension with the standard model, we here examine whether the observed 21-cm signal is instead consistent with the results of recent modeling based on the alternative Friedmann-Lemaitre-Robertson-Walker cosmology known as the R_h=ct universe, showing that--in this model--the CMB radiation might have been rethermalized by dust ejected into the IGM by the first-generation stars at redshift z < 16. We find that the requirements for this process to have occurred would have self-consistently established an equilibrium spin temperature T_s~3.4 K in the neutral hydrogen, via the irradiation of the IGM by deep penetrating X-rays emitted at the termination shocks of Pop III supernova remnants. Such a dust scenario has been strongly ruled out for the standard model, so the spin temperature (~3.3 K) inferred from the 21-cm absorption feature appears to be much more consistent with the R_h=ct profile than that implied by LCDM, for which adiabatic cooling would have established a spin temperature T_s(z=17.2)~

                                               a. 6 K      b. 9k       c. 10k       d.  1K.

Q68. The Lightning Ball Double Observation that Lands in Water by Prof. Dr. Kotcherlakota Lakshmi Narayana, (Retd. Prof of Physics, Shivaji University, Kolhapur-416004, Maharashtra State, during June 1966 - July 2000 India. Currently at 17-11-10, Narasimha Ashram, Official Colony, Maharanipeta.P.O. Andhra Pradesh}: ABSTRACT:Lightning Ball Observation at two different places, one at Kolhapur and the other at Visakhapatnam at my residence Narsimha Ashram.  Observed, Lightning Balls are Plasmas, but shaped in terms of flying round balls (as observed in Kolhapur) or just travel straight down in splendid fashion, (as observed at Narasimha Ashram) very powerful balls of tremendous energy, to splatter the lids to enter the Water. The Lightning Ball Bolts exist even on the Satellite, Celestial bodies like the Moon, Mars, and other planetary systems. Perhaps their existence even in the remote Astrophysical and Astronomical bodies need to be studied extensively. Water is used by orthodox Indians to perform puja four times a day, significance of which need to be thoroughly probed. Presence of water has been suggested even in the remote distant objects as Japanese recently found the presence of water in their celestial body observations. Dense Plasma clouds surrounding several celestial entities possibly have presence of water molecules. Why is that water occupied such a significant role in the heavenly                           a. terms     b. fashion      c.  splatter      d. bodies? 

 

Q69. arXiv:2103.13706 [astro-ph.SR] [Submitted on 25 Mar 2021]:Thu, 25 Mar 2021 09:28:58 UTC (6,215 KB):   New binaries from the SHINE survey. M. Bonavita, et al ., :ABSTRACT: We present the multiple stellar systems observed within the SpHere INfrared survey for Exoplanet (SHINE). SHINE searched for substellar companions to young stars using high contrast imaging. Although stars with known stellar companions within SPHERE field of view (<5.5 arcsec) were removed from the original target list, we detected additional stellar companions to 78 of the 463 SHINE targets observed so far. 27% of the systems have three or more components. Given the heterogeneity of the sample in terms of observing conditions and strategy, tailored routines were used for data reduction and analysis, some of which were specifically designed for these data sets. We then combined SPHERE data with literature and archival ones, TESS light curves and Gaia parallaxes and proper motions, to characterise these systems as completely as possible. Combining all data, we were able to constrain the orbits of 25 systems. We carefully assessed the completeness of our sample for the separation range 50-500 mas (period range a few years - a few tens of years), taking into account the initial selection biases and recovering part of the systems excluded from the original list due to their multiplicity. This allowed us to compare the binary frequency for our sample with previous studies and highlight some interesting trends in the mass ratio and period distribution. We also found that, for the few objects for which such estimate was possible, the values of the masses derived from dynamical arguments were in good agreement with the model predictions. Stellar and orbital spins appear fairly well aligned for the 12 stars having enough data, which favour a disk fragmentation origin. Our results highlight the importance of combining different techniques when tackling complex problems such as the formation of binaries and show how large samples can be useful for more than one 

                       a.  model   b. purpose   c. possibility    d. constraint. 

Q70. arXiv:2103.13750 [gr-qc]: [Submitted on 25 Mar 2021]: Thu. 25 March. 2021 11:06:55 UTC(48 KB): Constraining the Generalized Uncertainty Principle with the light twisted by rotating black holes and M87*. Fabrizio Tamburini, Fabiano Feleppa, Bo Thidé.   :ABSTRACT: We test the validity of the Generalized Heisenberg's Uncertainty principle in the presence of strong gravitational fields nearby rotating black holes; Heisenberg's principle is supposed to require additional correction terms when gravity is taken into account, leading to a more general formulation also known as the Generalized Uncertainty Principle. Using as probe electromagnetic waves acquiring orbital angular momentum when lensed by a rotating black hole, we find from numerical simulations a relationship between the spectrum of the orbital angular momentum of light and the corrections needed to formulate the Generalized Uncertainty Principle, here characterized by the rescaled parameter β0, a function of the Planck's mass and the bare mass of the black hole. Then, from the analysis of the observed twisted light due to the gravitational field of the compact object observed in M87*, we find new limits for the parameter β0. With this method, complementary to black hole shadow circularity analyses, we obtain more precise limits from the experimental data of M87*, confirming the validity of scenarios compatible with General Relativity, within the uncertainties due to the experimental errors present in EHT data and those due to the numerical simulations and 

                          a. analysis    b. predictions    c. principles      d.  limits.

Q71. arXiv:2103.15857 [astro-ph.SR]: [Submitted on 29 Mar 2021]: Mon, 29 Mar 2021 18:07:10 UTC (2,908 KB): Infrared variable stars in the compact elliptical galaxy M32. O. C. Jones, C. Nally, M. J. Sharp, I. McDonald, M. L. Boyer, M. Meixner, F. Kemper, A. M. N. Ferguson, S. R. Goldman, R. M. Rich. :ABSTRACT: Variable stars in the compact elliptical galaxy M32 are identified, using three epochs of photometry from the Spitzer Space Telescope at 3.6 and 4.5 μm, separated by 32 to 381 days. We present a high-fidelity catalogue of sources detected in multiple epochs at both 3.6 and 4.5 μm, which we analysed for stellar variability using a joint probability error-weighted flux difference. Of these, 83 stars are identified as candidate large-amplitude, long-period variables, with 28 considered high-confidence variables. The majority of the variable stars are classified as asymptotic giant branch star candidates using colour-magnitude diagrams. We find no evidence supporting a younger, infrared-bright stellar population in our M32 

                                      a. galaxy     b. variable     c. field       d. threshold.

Q72. arXiv:2103.16191 [astro-ph.IM]: [Submitted on 30 Mar 2021]: Tue, 30 Mar 2021 09:17:57 UTC (428 KB): ABSTRACT:  In the quest of the DM particles which can be populating our galactic halo, one of the approaches followed is to register the scattering of those particles in a suitable detector. For this direct detection of DM, experiments based on noble liquids or solid-state cryogenic detectors, with increasing target mass and sophistication, have produced very relevant (even if negative) results for years. But complementary searches are developed based on other detection technologies; smaller scale experiments, focused on different physics cases, are indeed a very active field too. The identification of distinctive signatures of DM interaction, like the annual modulation in the rates or the signal directionality, would help to confirm a DM detection. Relevant results have been presented by NaI(Tl) experiments, ANAIS-112 and COSINE-100, aimed to independently verify using the same target the DAMA/LIBRA annual modulation result observed over two decades; there are underway other NaI(Tl) projects too with attractive particular features. Although having higher background levels and energy threshold than other detectors, NaI(Tl) scintillators offer the robust and stable operation and the  possibility of accumulating large target mass required in the investigation of the DM annual modulation signal. The construction of a DM detector sensitive to directionality (and then capable of proving the galactic origin of a potential signal) is hard, as short tracks must be imaged with good resolution. Low-pressure TPCs equipped with different readouts (MWPCs, Micromegas, µPICs, optical CCDs, . . . ) and nuclear emulsions are being implemented. Modest energy thresholds have been achieved in this type of detectors and collecting large exposures can be difficult, but medium-size TPC prototypes (having volumes from 0.1 to 1 m3 ) have already been developed and relevant progress is being achieved. For SI DM-nucleon cross sections, the best limits for masses above a few GeV/c^2 come presently from XENON1T; but at lower masses and when considering SD interaction and also electron scattering, the leading results are obtained from several different detection technologies: solid-state cryogenic detectors (scintillating bolometers, Ge and Si crystals), liquid noble detectors (Xe, Ar) operated in S2-only mode (charge collection) but also purely ionization detectors (CCDs, Ge and gas detectors) and bubble chambers. Although in some cases having a large target mass is complicated, the achievement of extremely low energy thresholds, the inclusion of targets with low mass and/or the consideration of several interaction15 of 23 channels are the assets for exploring low mass DM; other new technologies are under study to further improve the detector performance. It has been attempted to show here that small scale experiments have already released very competitive results in the direct detection of DM and, surely, more will come in the next future. Complementary experiments based on different technologies are required to guarantee the exploration of the wide range of possible DM candidate 

                         a.     masses     b. particles     c. detectors     d. performance.

Q73. Apr. 3, 2021:  MY OBSERVATION AT VISAKHAPATNAM from 9 PM to 10:30 PM on 3rd April 2021. "An unusual RED lightning and minimal thunder, accompanied by severe white-Bluish lightning  from 9 PM to 9:30 PM, but later continued till 10:30 PM with subdued thunder and lightning of both types the RED and usual lightning:"

Apr. 3, 2021: At 9 PM: There was a severe rain and thundershower around 9 PM on the night of 3rd. I was busy using the Laptop, and all of a sudden the lights were off and I was forced to shutdown the Laptop. Actually there was a sudden frightening noise that startled me while I was working on the Laptop. Next day from Newspapers, I came to know that the thunder shower started around 8 PM. But since I was busy with the Laptop, I have not paid attention to the sudden burst of the rain. All of a sudden the loud noise made me to wonder what happened. When I looked up I saw my plug point connection to the modem was out, in fact,  it flied away. From 9 PM to almost 10:30 PM I was watching the heavy rain sitting on the chair in the big hall and wondered how the lightning was occasionally RED. The usual lightning was also there with the bright and violent splash of white light. "What attracted my attention was the RED light that was not as high as originating like the splash of the white-bluish lightning". I am completely amazed since it was the first time I noticed the RED flashes of lightning unlike the white-blueish lightning. I have found that the RED flashes occurred almost once in 3 or 4 minutes. The rain was a roaring splash of the vehement rainfall that was at its peak from 9 PM to about 9:30PM but later it dwindled as the usual heavy rain. That rain continued till the 10:30 PM, with the distant thunders and graced with occasional splashes of RED lightning. I wondered since it was FIRST TIME, I noticed the RED lightning, I watched it sitting in a comfortable chair and watched the splendor of the lightning and thunder. The RED light has not produced that much of severe thunder as the usual case, with the shiny silver lining of white-bluish lightning. Next day while going through my MOBILE PHONE survey of OPERA NEWS, I came to know that the lightning of a similar kind was in Madras also. The Tamilnadu lightning and obviously the Vizag lightning both moved towards the SEA. Presumably, they joined the Thunder and Lightning, from Tamil Nadu that moved towards the Myanmar. My Laptop totally failed and, the resource person couldn't repair it till the morning of Tuesday i.e., 6th April 2021. My original version of this writing totally disappeared from my Laptop, due to the sudden lights off and on the night of the 6th, I am able to recast it and presented in my web. Many trees and houses and sheds have been damaged in Visakhapatnam and in the last few days the accounts of these mishaps due to the heavy rain were presented in several newspapers, especially Telugu papers gave exhaustive and lengthy descriptions for nearly three days", by Prof. Dr. Kotcherlakota Lakshmi Narayana. Presented in my Facebook also.

                                                             

                                          Fig.9 The plug jumped off the socket

and the power was failure at 9 PM on 3rd April night,

possibly due to the RED lightning that struck the installion.

        a. RED LIGHTNING   b. Blue lightning  c. Thunder   d. Installation.

Q74. MNRAS 000, 1–6 (2021) Preprint 13 April 2021 Compiled using MNRAS LATEX style file v3.0. A new measurement of the Hubble constant using Fast Radio Bursts by Steffen Hagstotz;, Robert Reischke; and Robert Lilow: ABSTRACT:  A new measurement of the Hubble constant 𝐻0 based on the dispersion measure – redshift relation of fast radio bursts (FRBs). The method is similar to the determination of 𝐻0 from the e. luminosity – redshift relation of calibrated SN Ia. The total DM is dominated by the cosmological signal for redshifts 𝑧 > 0.3. With the current small sample of nine FRBs with known host galaxies, we constrain the Hubble constant to 𝐻0 = 62.3±9.1 km s^−1 Mpc^−1 . We also limit the analysis to the six events with the most reliable host identification (the gold sample), with an almost identical result of 𝐻0 = 62.5 ± 10.1 km s^−1 Mpc^−1 , since most of the excluded FRBs are located at low redshifts. The current main limitations lie in the very small number of available events with sufficient localisation and in the uncertainty about the DM contribution from the host galaxy. Both of these can be solved by a larger sample of localised FRBs. In fact, dedicated searches with excellent angular resolution are expected to detect hundreds of bursts and their host galaxies over the next years. We demonstrate with a forecast that, with the data available in the near future, it is possible to set precision constraints on 𝐻0 fully independent from the CMB or other cosmological measurements, while simultaneously determining the stochastic host halo contribution. Since the cosmological and the stochastic contributions to the DM scale differently with redshift, a sample of a few hundred FRBs can reliably distinguish the two effects. This demonstrates the potential of FRBs for precision measurements of cosmological 

                     a. events    b. scenario     c. FRBs      d. parameters.

Q75. arXiv:2104.05142 [astro-ph.HE]: [Submitted on 12 Apr 2021]: Discovery of the most X-ray luminous quasar SRGE J170245.3+130104 at redshift z≈5.5 by G.A. Khorunzhev et al, ABSTRACT: SRGE J170245.3+130104 was discovered by the eROSITA telescope aboard the SRG space observatory on March 13-15, 2020 during the first half-year scan of its all-sky X-ray survey. The optical counterpart of the X-ray source was photometrically identified as a distant quasar candidate at z≈5.5. Follow-up spectroscopic observations, done in August/September 2020 with the SCORPIO-II instrument at the BTA 6-m telescope, confirmed that SRGE J170245.3+130104 is a distant quasar at redshift z=5.466. The X-ray luminosity of the quasar during the first half-year scan of the eROSITA all-sky survey was 3.6(+2.1/−1.5)×10^46 erg/s (in the 2-10 keV energy range), whereas its X-ray spectrum could be described by a power law with a slope of Γ=1.8(+0.9/−0.8). Six months later (September 13-14, 2020), during the second half-year scan of the eROSITA all-sky survey, the quasar was detected again and its X-ray luminosity had decreased by a factor of 2 (at the ≈1.9σ confidence level). The SRGE J170245.3+130104 proves to be the most X-ray luminous among all known X-ray quasars at z>5. It is also one of the radio-loudest distant quasars (with radio-loudness R∼10^3), which may imply that it is a blazar. In the Appendix,  we present the list of all z>5 quasars detected in X-rays 

                      a. years ago   b. to date     c. recently   d. one month ago. 

Q76. arXiv:2104.05174 [astro-ph.SR]: [Submitted on 12 Apr 2021]: Three-dimensional magnetic reconnection in astrophysical plasmas.  Ting Li, Eric Priest, Ruilong Guo. ABSTRACT:  Magnetic reconnection is a fundamental process in a laboratory, magnetospheric, solar and astrophysical plasma, whereby magnetic energy is converted into heat, bulk kinetic energy and fast particle energy. Its nature in two dimensions is much better understood than in three dimensions (3D), where its character is completely different and has many diverse aspects that are currently being explored. Here we focus on the magnetohydrodynamics of 3D reconnection in the plasma environment of the solar system, especially solar flares. The theory of reconnection at null points, separators and quasi-separators is described, together with accounts of numerical simulations and observations of these three types of reconnection. The distinction between separator and quasi-separator reconnection is a theoretical one that is unimportant for the observations of energy release. A new paradigm for solar flares, in which 3D reconnection plays a central role, is 

                            a proposed    b. sought    c. thought     d. released.  

Q77.arXiv:2104.07044 [astro-ph.GA]: [Submitted on 14 Apr 2021]:Wed, 14 Apr 2021 18:00:07 UTC (87 KB): Stellar fluctuations of a stellar system. Jun Yan Lau, James Binney. :ABSTRACT: The excursions of star clusters and galaxies around statistical equilibria are studied. For an ergodic model with monotone decreasing DF Antonov's Hermitian operator on six-dimensional phase space has the normal modes as its eigenfunctions. The excitation energy of the system is just the sum of the (positive) energies associated with each normal mode. The positivity of modal energies opens the way to modelling the thermal properties of clusters in close analogy with those of crystals. Formulae are given for the DFs of modes, which are of the type first described by van Kampen rather than Landau. Each mode comprises the response of non-resonant stars to driving by the gravitational field of stars on a group of resonant tori. The structure of each mode is sensitive to the degree of self gravity. The emergence of global distortions in N-body models when particles are started from an analytical equilibrium is explained in terms of the interplay of normal

                                        a. scatter   b. phases   c. modes   d. sums.

Q78. arXiv:2104.07107 [astro-ph.EP]: [Submitted on 14 Apr 2021]:Wed, 14 Apr 2021 20:19:03 UTC (2,352 KB): Infrared spectroscopy of clathrate hydrates for planetary science: the ethylene case. Emmanuel Dartois. :ABSTRACT: Hydrocarbons are observed in the gas or solid phases of solar system objects, including comets, Trans-Neptunian Objects, planets and their moons. In the presence of water ice in these environments, hydrocarbons-bearing clathrate hydrates could form. In clathrate hydrates, guest molecules are trapped in crystalline water cages of different sizes, a phase used in models of planetary (sub-)surfaces or icy bodies such as comets. The phases in presence, the potential estimate of abundances of hydrocarbon species, the spectroscopic behaviour of hydrocarbon species in the different phases must be recorded to provide reference spectra for the comparison with remote observations. We show in this study the specific encaged ethylene signatures, with bands similar in position, but shifted from the pure ethylene ice spectrum. They show a marked temperature dependence both in position and width. Some vibrational modes are activated in the infrared by interaction with the water ice 

                              a.  system   b. cages    c. spectra    d. observations.

Q79. arXiv:2104.07366 [hep-ph]: [Submitted on 15 Apr 2021]:Thu, 15 Apr 2021 10:48:22 UTC (405 KB): Minimal SU(6) Gauge-Higgs Grand Unification. Andrei Angelescu, Andreas Bally, Simone Blasi, Florian Goertz. :ABSTRACT: We present a minimal viable Gauge-Higgs Grand Unification scenario in warped space based on a SU(6) bulk symmetry - unifying the gauge symmetries of the SM and their breaking sector. We show how the issue of light exotic new states is eliminated by appropriately breaking the gauge symmetry on the UV and IR boundaries by either brane scalars or gauge boundary conditions. The SM fermion spectrum is naturally reproduced including Dirac neutrinos and we compute the Higgs potential at one-loop, finding easily solutions with a realistic mh∼125 GeV. The problem of proton decay is addressed by showing that baryon number is a hidden symmetry of the model. Among the phenomenological consequences, we highlight the presence of a scalar leptoquark and a scalar singlet. The usual X,Y gauge bosons from SU(5) GUTs are found at collider accessible 

                        a. masses   b. numbers     c. consequences    d. baryons.

Q80. arXiv:2104.07222 [physics.optics]: [Submitted on 15 Apr 2021]:Thu, 15 Apr 2021 03:48:35 UTC (3,829 KB): Prospects and challenges of quantum emitters in 2D materials. Shaimaa I. Azzam, Kamyar Parto, Galan Moody. :ABSTRACT: The search for an ideal single-photon source has generated significant interest in discovering novel emitters in materials as well as developing new manipulation techniques to gain better control over the emitters' properties. Quantum emitters in atomically thin two-dimensional (2D) materials have proven very attractive with high brightness, operation under ambient conditions, and the ability to be integrated with a wide range of electronic and photonic platforms. This perspective highlights some of the recent advances in quantum light generation from 2D materials, focusing on hexagonal boron nitride and transition metal dichalcogenides (TMDs). Efforts in engineering and deterministically creating arrays of quantum emitters in 2D materials, their electrical excitation, and their integration with photonic devices are discussed. Lastly, we address some of the challenges the field is facing and the near-term efforts to tackle them. We provide an outlook towards efficient and scalable quantum light generation from 2D materials towards controllable and addressable on-chip quantum 

                          a. detectors    b.  chips   c. sources     d. generators.

Q81. arXiv:2104.07772 [physics.optics]: Thu, 15 Apr 2021 21:04:10 UTC (1,307 KB): [Submitted on 15 Apr 2021]: Active Magnetoplasmonics with Transparent Conductive Oxide Nanocrystals,  Alessio Gabbani, Claudio Sangregorio, Bharat Tandon, Angshuman Nag, Massimo Gurioli. :ABSTRACT: Magnetoplasmonics is highly promising to devise active optical elements: modulating the plasmon resonance condition with magnetic field can boost the performance of refractometric sensors and nanophotonic optical devices. Nevertheless, real life applications are hampered by the magnetoplasmonic trilemma: 1) a good plasmonic metal has sharp optical resonances but low magneto-optical response; 2) a magnetic metal has strong magneto-optical response but a very broad plasmonic resonance; 3) mixing the two components degrades the quality of both features. To overcome the trilemma, we use a different class of materials, transparent conductive oxide nanocrystals (NCs) with plasmonic response in the near infrared. Although non-magnetic, they combine a large cyclotron frequency (due to small electron effective mass) with sharp plasmonic resonances. We benchmark the concept with F- and In- doped CdO (FICO) and Sn-doped In2O3 (ITO) NCs to boost the magneto-optical Faraday rotation and ellipticity, reaching the highest magneto-optical response for a non-magnetic plasmonic material, and exceeding the performance of state-of-the-art ferromagnetic nanostructures. The magnetoplasmonic response of these NCs was rationalized with analytical model based on the excitation of circular magnetoplasmonic modes. Finally, proof of concept experiments demonstrated the superior performance of FICO NCs with respect to current state of the art in magnetoplasmonic refractometric sensing, approaching the sensitivity of leading localized plasmon refractometric methods with the advantage of not requiring complex curve 

                              a. fitting     b. approximation  c. mode   d. boost.

Q82. arXiv:2104.08011 [physics.plasm-ph]: Fri, 16 Apr 2021 10:13:02 UTC (3,178 KB): [Submitted on 16 Apr 2021]: Infrared spectroscopy of surface charges in plasma-facing dielectrics. K. Rasek, F. X. Bronold, H. Fehske.  :ABSTRACT: We propose to measure the surface charge accumulating at the interface between a plasma and a dielectric by infrared spectroscopy using the dielectric as a multi-internal reflection element. The surplus charge leads to an attenuation of the transmitted signal from which the magnitude of the charge can be inferred. Calculating the optical response perturbatively in first order from the Boltzmann equation for the electron-hole plasma inside the solid, we can show that in the parameter range of interest a classical Drude term results. Only the integrated surface charge enters, opening up thereby a very efficient analysis of measured

                                 a. inferrence   b. signal    c. data    d. range. 

Q83.arXiv:2104.08128 [physics.app-ph]: Fri, 16 Apr 2021 14:20:11 UTC (4,616 KB) [Submitted on 16 Apr 2021]: Room temperature single-photon emitters in silicon nitride. Alexander Senichev  et al., :ABSTRACT: Single-photon emitters are essential for enabling several emerging applications in quantum information technology, quantum sensing and quantum communication. Scalable photonic platforms capable of hosting intrinsic or directly embedded sources of single-photon emission are of particular interest for the realization of integrated quantum photonic circuits. Here, we report on the first-time observation of room-temperature single-photon emitters in silicon nitride (SiN) films grown on silicon dioxide substrates. As SiN has recently emerged as one of the most promising materials for integrated quantum photonics, the proposed platform is suitable for scalable fabrication of quantum on-chip devices. Photophysical analysis reveals bright (>105 counts/s), stable, linearly polarized, and pure quantum emitters in SiN films with the value of the second-order autocorrelation function at zero time delay g(2)(0) below 0.2 at room temperatures. The emission is suggested to originate from a specific defect center in silicon nitride due to the narrow wavelength distribution of the observed luminescence peak. Single-photon emitters in silicon nitride have the potential to enable direct, scalable and low-loss integration of quantum light sources with the well-established photonic on-chip platform.

                          a. enable    b. platform     c. center    d. peak.

Q84.arXiv:2104.09517 [hep-ph]: [Submitted on 19 Apr 2021]:Mon, 19 Apr 2021 18:00:01 UTC (832 KB): Closing the window on WIMPy inelastic dark matter: journey to the end of the periodic table. Ningqiang Song, Serge Nagorny, Aaron C. Vincent. :ABSTRACT: We explore the reach of low-background experiments made of small quantities of heavy nuclear isotopes in probing the parameter space of inelastic dark matter that is kinematically inaccessible to classic direct detection experiments. Through inelastic scattering with target nuclei, dark matter can yield a signal either via nuclear recoil or nuclear excitation. We present new results based on this approach, using data from low-energy gamma quanta searches in low-background experiments with Hf and Os metal samples, and measurements with CaWO4 and PbWO4 crystals as scintillating bolometers. We place novel bounds on WIMPy inelastic dark matter up to mass splittings of about 640 keV, and provide forecasts for the reach of future 

                           a.   trends    b. thoughts    c. experiments      d. novelties.

Q85.arXiv:2010.15836 [hep-ph]:  [Submitted on 29 Oct 2020 (v1), last revised 20 Apr 2021 (this version, v3)]: Radio-frequency Dark Photon Dark Matter across the Sun. Haipeng An, Fa Peng Huang, Jia Liu, Wei Xue. :ABSTRACT: Dark photon as an ultralight dark matter candidate can interact with the Standard Model particles via kinetic mixing. We propose to search for the ultralight dark photon dark matter using radio telescopes with solar observations. The dark photon dark matter can efficiently convert into photons in the outermost region of the solar atmosphere, the solar corona, where the plasma mass of photons is close to the dark photon rest mass. Due to the strong resonant conversion and benefiting from the short distance between the Sun and the Earth, the radio telescopes can lead the dark photon search sensitivity in the mass range of 4×10^−8−4×10−6eV, corresponding to the frequency 10−1000MHz. As a promising example, the operating radio telescope LOFAR can reach the kinetic mixing ϵ∼10^−13 (10^−14) within 1 (100) hour solar observations. The future experiment SKA phase 1 can reach ϵ∼10^−16−10^−14 with 1 hour solar 

                         a. findings    b. observation   c. conversion    d. resonance.

Q86. arXiv:2104.10354 [astro-ph.CO]:  Wed, 21 Apr 2021 05:12:32 UTC (23,239 KB)[Submitted on 21 Apr 2021]:: Observational constraints on the cosmological expansion rate and spatial curvature. Joseph Ryan. :ABSTRACT: Observations conducted over the last few decades show that the expansion of the Universe is accelerating. In the standard model of cosmology, this accelerated expansion is attributed to a dark energy in the form of a cosmological constant. It is conceivable, however, for the dark energy to exhibit mild dynamics (so that its energy density changes with time rather than having a constant value), or for the accelerated expansion of the Universe to be caused by some mechanism other than dark energy. In this work I will investigate both of these possibilities by using observational data to place constraints on the parameters of simple models of dynamical dark energy as well as cosmological models without dark energy. I find that these data favor the standard model while leaving some room for dynamical dark energy. The standard model also holds that the Universe is flat on large spatial scales. The same observational data used to test dark energy dynamics can be used to constrain the large-scale curvature of the Universe, and these data generally favor spatial flatness, with some mild preference for spatial curvature in some data combinations. GRB measurements are consistent with those of the other probes we considered, and so can be combined with them, extending the range of cosmological model parameter constraints into a little-studied region of redshift space. We hope that, with the coming of more GRB observations in the future, these higher-redshift constraints can be used to pin down the dynamics of dark energy accurately and

                                 a. results    b. guesses   c. features     d. precisely.             

 Q87. arXiv:2104.10695 [astro-ph.CO]: Wed, 21 Apr 2021 18:00:05 UTC (1,150 KB)Submitted on 21 Apr 2021]: 21 cm Forest Constraints on Primordial Black Holes. Pablo Villanueva-Domingo, Kiyotomo Ichiki. :ABSTRACT: Primordial black holes (PBHs) as part of the Dark Matter (DM) would modify the evolution of large-scale structures and the thermal history of the universe. Future 21 cm forest observations, sensitive to small scales and the thermal state of the Inter Galactic Medium (IGM), could probe the existence of such PBHs. In this article, we show that the shot noise isocurvature mode on small scales induced by the presence of PBHs can enhance the amount of low mass halos, or minihalos, and thus, the number of 21 cm absorption lines. However, if the mass of PBHs is as large as MPBH≳10M⊙, with an abundant enough fraction of PBHs as DM, fPBH, the IGM heating due to accretion onto the PBHs counteracts the enhancement due to the isocurvature mode, reducing the number of absorption lines instead. The concurrence of both effects imprints distinctive signatures in the number of absorbers, allowing to bound the abundance of PBHs. We compute the prospects for constraining PBHs with future 21 cm forest observations, finding achievable competitive upper limits on the abundance as low as fPBH∼10^−3 at MPBH=100M⊙, or even lower at larger masses, in unexplored regions of the parameter space by current probes. The impact of astrophysical X-ray sources on the IGM temperature is also studied, which could potentially weaken the 

                          a. bands   b. bounds   c. observations     d. abundance.

Q88. arXiv:2104.10894 [astro-ph.SR]: Thu, 22 Apr 2021 06:53:28 UTC (593 KB)[Submitted on 22 Apr 2021]: Chemical composition of stars with massive planets. T. Mishenina, N. Basak, V. Adibekyan, C. Soubiran, V. Kovtyukh. :ABSTRACT: Stellar parameters of 25 planet-hosting stars and abundances of Li, C, O, Na, Mg, Al, S, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Zn, Y, Zr, Ba, Ce, Pr, Nd, Sm and Eu, were studied based on homogeneous high resolution spectra and uniform techniques. The iron abundance [Fe/H] and key elements (Li, C, O, Mg, Si) indicative of the planet formation, as well as the dependencies of [El/Fe] on Tcond, were analyzed. The iron abundances determined in our sample stars with detected massive planets range within -0.3<[Fe/H]<0.4. The behaviour of [C/Fe], [O/Fe], [Mg/Fe] and [Si/Fe] relative to [Fe/H] is consistent with the Galactic Chemical Evolution trends. The mean values of C/O and [C/O] are <C/O>= 0.48 +/-0.07 and <[C/O]>=-0.07 +/-0.07, which are slightly lower than solar ones. The Mg/Si ratios range from 0.83 to 0.95 for four stars in our sample and from 1.0 to 1.86 for the remaining 21 stars. Various slopes of [El/Fe] vs. Tcond were found. The dependencies of the planetary mass on metallicity, the lithium abundance, the C/O and Mg/Si ratios, and also on the [El/Fe]-Tcond slopes were 

                                a. thought    b. speculated  c . considered   d. abundant.

Q89. arXiv:2104.10686 [hep-th]:  Wed, 21 Apr 2021 18:00:00 UTC (237 KB)[Submitted on 21 Apr 2021]: Gravitational Footprints of Black Holes and Their Microstate Geometries. Ibrahima Bah, Iosif Bena, Pierre Heidmann, Yixuan Li, Daniel R. Mayerson.:ABSTRACT: We construct a family of non-supersymmetric extremal black holes and their horizonless microstate geometries in four dimensions. The black holes can have finite angular momentum and an arbitrary charge-to-mass ratio, unlike their supersymmetric cousins. These features make them and their microstate geometries astrophysically relevant. Thus, they provide interesting prototypes to study deviations from Kerr solutions caused by new horizon-scale physics. In this paper, we compute the gravitational multipole structure of these solutions and compare them to Kerr black holes. The multipoles of the black hole differ significantly from Kerr as they depend non-trivially on the charge-to-mass ratio. The horizonless microstate geometries have the same multipoles as their corresponding black hole, with small deviations set by the scale of their

                     a. microstructure    b. relevance    c. solutions    d. structures.

Q90.  arXiv:2104.10779 [physics.plasm-ph]:  Wed, 21 Apr 2021 22:05:07 UTC (86 KB)Submitted on 21 Apr 2021]: Pair production seeded by electrons in noble gases as a method for the laser intensity diagnostics. I. A. Aleksandrov, A. A. Andreev. :ABSTRACT: In this study we explore the possibility of using the process of electron-positron pair creation in strong laser fields as a tool for measuring the intensity of the corresponding laser radiation. In the initial state we consider either free electron gas or gas of neutral xenon, the electrons of which get ionized. Once these seed electrons gain sufficient energy in the external laser field, they can emit high-energy photons which subsequently decay producing electron-positron pairs via the Breit-Wheeler mechanism. By detecting the resulting positrons, one can recover the value of the laser intensity by means of the one-to-one correspondences deduced in the present investigation. We analyze two different configurations of the external field: the setup involving an individual focused laser pulse and the combination of two counterpropagating laser pulses. Performing numerical calculations and analyzing their accuracy, we demonstrate that based on our estimates, the laser intensity can be determined within the range 10^23-10^26 W/cm^2 with a relative uncertainty of 10-

                                            a.   40%       b.50%      c. 100%      d. 10%.

Q91. arXiv:2104.11077 [physics.gen-ph]:  Tue, 20 Apr 2021 07:36:48 UTC (13 KB): [Submitted on 20 Apr 2021]: Quantum cosmology with symmetry analysis for quintom dark energy model. Sourav Dutta, Muthusamy Lakshmanan, Subenoy Chakraborty. :ABSTRACT: Quantum cosmology with quintom dark energy model has been investigated in the present work using symmetry analysis of the underlying physical system. In the background of the flat FLRW model quintom cosmological model has been studied using Noether symmetry and appropriate conserved charge is obtained. The Wheeler-DeWitt (WD) equation is constructed on the minisuperspace and solutions are obtained using conserved 

                             a. energy   b. symmetry   c. cosmology   d. charge. 

Q92. May. 07, 2021 at 6 PM:  Prof. K.R.Rao D.Sc.(Madras) D.Sc. (London) from 1919 to 1972 June 20, guided more than about 70 Doctoral Candidates at Andhra University, Waltair. He was in London, and Sweden during the years 1928 to 1930, when he achieved D.Sc. (London). What is amazing is that he guided students from one end of the spectrum, namely Radio Waves, through intermediate ranges to Cosmic Rays, and many foreighn scientists visited his laboratories  in Andhra University, that claimed world wide recognition. Many of his students migrated to the USA and other countries. See his biography outlined by the present author Prof. Dr. Kotcherlakota Lakshmi Narayana in a series of articles. One British Lady took a lot of pains to collect all his original publications made in London etc., and made a volume of astounding memories of extraordinary genius. Curtis was allowed but Prof.K.R.Rao D.Sc.(London))not permitted to board the ship to travel to the USA in 1930.  What I propose now that Prof. K. R. Rao thought of extended spectrum from far below the Radio waves and as well far beyond the Cosmic Rays. He cursorily mentioned it in his D.Sc. Thesis of Madras University, in the years 1919 to 1924, in spite of most research work he carried out in Vizianagaram and Visakhapatnam, with visits to Thiruvananthapuram. Amazingly he thought of Quantum Spread of the spectra and with limited resources he made very interesting statements about the observation of the spectrums.  Now I suggest that the Electromagnetic spectrum has a novel feature, of associated Quantum Spread, with the spectrum extending below the Radio Waves and as well a far reaching extension above the Cosmic Rays extending to unknown ...................... Forward, it to all whom you think interested in such writeups.  

                     a. magnitudes     b. heights     c. lengths    d. spectra.

Q93.arXiv:2105.09351 [astro-ph.HE]L [Submitted on 19 May 2021]: Wed, 19 May 2021 18:37:07 UTC (277 KB): The novel mechanism of pair creation in pulsar magnetospheres. Z. Osmanov, G. Machabeli, N. Chkheidze.: ABSTRACT: In this paper we study the possibility of efficient pair production in a pulsar's magnetosphere. It has been shown that by means of the relativistic centrifugal force the electrostatic field exponentially amplifies. As a result the field approaches the Schwinger limit leading to pair creation process in the light cylinder area where the effects of rotation are very efficient. Analysing the parameters of the normal period (∼1 sec) pulsars we have found that the process is so efficient that the number density of electron-positron pairs exceeds the Goldreich-Julian density by five orders of magnitude. George Machabeli [view email].

                           a. magnitude   b. mechanism     c. possibility      d.  rotation.

Q94. arXiv:2105.09419 [astro-ph.SR] [Submitted on 19 May 2021]:Jenna Samra [view email]:  Wed, 19 May 2021 22:13:53 UTC (9,875 KB):  The Airborne Infrared Spectrometer: Development, Characterization, and the 21 August 2017 Eclipse Observation. Jenna E. Samra, Vanessa Marquez, Peter Cheimets, Edward E. DeLuca, Leon Golub, James W. Hannigan, Chad A. Madsen, Alisha Vira. :ABSTRACT: On August 21, 2017, the Airborne Infrared Spectrometer (AIR-Spec) observed the total solar eclipse at an altitude of 14 km from aboard the NSF/NCAR Gulfstream V research aircraft. The instrument successfully observed the five coronal emission lines that it was designed to measure: Si X 1.431 μm, S XI 1.921 μm, Fe IX 2.853 μm, Mg VIII 3.028 μm, and Si IX 3.935 μm. Characterizing these magnetically sensitive emission lines is an important first step in designing future instruments to monitor the coronal magnetic field, which drives space weather events as well as coronal heating, structure, and dynamics. The AIR-Spec instrument includes an image stabilization system, feed telescope, grating spectrometer, and slit-jaw imager. This paper details the instrument design, optical alignment method, image processing, and data calibration approach. The eclipse observations are described and the available data are 

                   a. elaborated   b. summarized   c. explained    d. stressed.

Q95. arXiv:2105.09962 [astro-ph.HE]: Thu, 20 May 2021 18:00:05 UTC (4,165 KB)[Submitted on 20 May 2021]: Measuring Spin from Relative Photon Ring Sizes. Authors: Avery E. Broderick, Paul Tiede, Dominic W. Pesce, Roman Gold. :ABSTRACT: The direct detection of a bright, ring-like structure in horizon-resolving images of M87* by the Event Horizon Telescope is a striking validation of general relativity. The angular size and shape of the ring is a degenerate measure of the location of the emission region, mass, and spin of the black hole. However, we show that the observation of multiple rings, corresponding to the low-order photon rings, can break this degeneracy and produce mass and spin measurements independent of the shape of the rings. We describe two potential experiments that would measure the spin. In the first, observations of the direct emission and n=1 photon ring are made at multiple epochs with different emission locations. This method is conceptually similar to spacetime constraints that arise from variable structures (or hot spots) in that it breaks the near-perfect degeneracy between emission location, mass, and spin for polar observers using temporal variability. In the second, observations of the direct emission, n=1 and n=2 photon rings are made during a single epoch. For both schemes, additional observations comprise a test of general relativity. Thus, comparisons of Event Horizon Telescope observations in 2017 and 2018 may be capable of producing the first horizon-scale spin estimates of M87* inferred from strong lensing alone. Additional observation campaigns from future high-frequency, Earth-sized and space-based radio interferometers can produce high-precision tests of 

              a. special relativity   b. relativity     c. M87*      d. General Relativity.

Q96. arXiv:2103.02514 [quant-ph]: [v1] Wed, 3 Mar 2021 16:39:29 UTC (81 KB):[v2] Wed, 2 Jun 2021 14:05:45 UTC (82 KB):[Submitted on 3 Mar 2021 (v1), last revised 2 Jun 2021 (this version, v2)]: Heisenberg uncertainty relations for relativistic bosons. Iwo Bialynicki-Birula, Adam Prystupiuk. :ABSTRACT: This work completes the program started in \cite{bb1,bb2,bb3} to derive the Heisenberg uncertainty relation for relativistic particles. Sharp uncertainty relations for massive relativistic particles with spin 0 and spin 1 are derived. The main conclusion is that the uncertainty relations for relativistic bosons are markedly different from those for relativistic fermions. The uncertainty relations for bosons are based on the energy density. It is shown that the uncertainty relations based on the time-component of the four-current, as was have done in \cite{bb3} for electrons, are untenable because they lead to 

                           a. contradictions.  b. conclusions. c. relations   d. conclusions.

Q97. arXiv:2106.01479 [physics.atom-ph]: Wed, 2 Jun 2021 21:31:29 UTC (689 KB): [Submitted on 2 Jun 2021]: Two-dimensional three-body quadrupole-quadrupole interactions. Jianing Han :ABSTRACT: Similar to interactions between dipoles, or van der Waals interactions, quadrupole-quadrupole interactions are interactions between quadrupoles. In this article, we study the quadrupole interactions between highly excited atoms or Rydberg atoms. In addition, unlike many other calculations, in which the primary focus was on the one-dimensional two-body quadrupole-quadrupole interactions, the primary aim of this article is to study the two-dimensional few-body quadrupole-quadrupole interactions. Specifically, the two-dimensional three-body interactions are investigated. This research has many applications, such as quadrupole-blockade for quantum computing, creating molecules based on quadrupole 

            a. calculation     b. two dimensional    c. interactions  d. three body.

Q98. arXiv:2106.01346 [physics.gen-ph]: Tue, 1 Jun 2021 06:07:16 UTC (10 KB) [Submitted on 1 Jun 2021]: Matter without mass: do we really need the concept of mass? Luigi Foschini. ABSTRACT: Einstein's most famous equation -- E=mc2 -- generated a short-circuit between the concepts of mass and energy, which also affects other concepts like matter, radiation, and vacuum. Physics currently has a mixture of classical, relativistic, and quantum concepts of mass, which generates a great deal of confusion and many problems. Clear definitions need to be established if one wants to avoid ghost hunting. In particular, by abandoning the idea of mass and focusing on time and energy, some interesting implications are emerging. There might be an intriguing relationship between the dark energy, as the zero-point energy of the electromagnetic field, and the Cosmic Microwave Background epoch, as its horizon. This might also be the hint of an expanding and rotating universe. An observational test is proposed to verify this hypothesis. I would like to share some reflections on this topic, without claiming any conclusive 

                       a.  adoption      b. recipe      c. fact       d. hypothesis.

Q99.arXiv:2106.01565 [hep-th]:Thu, 3 Jun 2021 03:18:58 UTC (4,678 KB):  [Submitted on 3 Jun 2021]: Axion-like dark matter clouds around rotating black holes. Bartlomiej KIczek, Marek Rogatko: ABSTRACT: Numerical analysis of dark matter axion-like cloud in the vicinity of rotating black hole has been performed. The model where axion-like scalar field is non-trivially coupled to Maxwell field is studied in the spacetime of Kerr black hole in uniform magnetic field and in Kerr-Newman one. The dependence of scalar mass and black hole angular momentum on accumulation of axion dark matter cloud was given. It was revealed that condensation of the dark matter clouds is preferable for a very small mass of 

                                a. dark matter   b. dark clouds     c. large axion      d. axion.

Q100. arXiv:2106.09392 [physics.optics]: Thu, 17 Jun 2021 11:18:15 UTC (1,450 KB): [Submitted on 17 Jun 2021]: Preventing Corrosion of Aluminum Metal with Nanometer-Thick Films of Al2O3 Capped with TiO2 for Ultraviolet Plasmonics. Prithu Roy, et al., : ABSTRACT: Extending plasmonics into the ultraviolet range imposes the use of aluminum to achieve the best optical performance. However, water corrosion is a major limiting issue for UV aluminum plasmonics, as this phenomenon occurs significantly faster in presence of UV light, even at low laser powers of a few microwatts. Here we assess the performance of nanometer-thick layers of various metal oxides deposited by atomic layer deposition (ALD) and plasma-enhanced chemical vapor deposition (PECVD) on top of aluminum nanoapertures to protect the metal against UV photocorrosion. The combination of a 5 nm Al2O3 layer covered by a 5 nm TiO2 capping provides the best resistance performance, while a single 10 nm layer of SiO2 or HfO2 is a good alternative. We also report the influence of the laser wavelength, the laser operation mode and the pH of the solution. Properly choosing these conditions significantly extends the range of optical powers for which the aluminum nanostructures can be used. As application, we demonstrate the label-free detection of streptavidin proteins with improved signal to noise ratio. Our approach is also beneficial to promote the long-term stability of the aluminum nanostructures. Finding the appropriate nanoscale protection against aluminum corrosion is the key to enable the development of UV plasmonic applications in chemistry and 

                        a. physics    b. biology    c. mathematics    d. botany.

Q101. arXiv:2106.09239 [cond-mat.mes-hall]: Thu, 17 Jun 2021 04:13:57 UTC (238 KB)[Submitted on 17 Jun 2021]: ABSTRACT: Tilted Dirac cone effects and chiral symmetry breaking in a planar four-fermion model. Y. M. P. Gomes, Rudnei O. Ramos. Details: We analyze the chiral symmetry breaking in a planar four-fermion model with non-null chemical potential, temperature and including the effect of the tilt of the Dirac cone. The system is modeled with a (2+1)-dimensional Gross-Neveu-like interaction model in the context of the generalized Weyl Hamiltonian and its phase structure is studied in the meanfield and large-N approximations. Possible applications of the results obtained, e.g., in connection to graphene, are discussed. We also discuss the effect of an external magnetic field applied to the system, which can give rise to the appearance of the anomalous Hall effect and that is expected to arise in connection with two-dimensional Weyl and Dirac  

                         a. semimetals   b. fermions    c. agenda   d. samples.

Q102.arXiv:2106.09356 [quant-ph]: Thu, 17 Jun 2021 10:18:20 UTC (238 KB):  [Submitted on 17 Jun 2021]: Quantum Entanglement of Free Particles. Roumen Tsekov. The Schrodinger equation is solved for many free particles and their quantum entanglement is studied via correlation analysis. Converting the Schrodinger equation in the Madelung hydrodynamic-like form, the quantum mechanics is extended to open quantum systems by adding Ohmic friction forces. The dissipative evolution confirms correlation decay over time, but a new integral of motion is discovered, being appropriate for storing everlasting quantum 

                         a. criteria    b. entaglement    c. information   d. analysis.

Q103. arXiv:2106.09515 [astro-ph.HE]: Wed, 16 Jun 2021 15:36:54 UTC (4,425 KB): [Submitted on 16 Jun 2021]: A Neutron Star is born. Débora Peres Menezes. :ABSTRACT:    A neutron star was first detected as a pulsar in 1967. It is one of the most mysterious compact objects in the universe, with a radius of the order of 10 km and masses that can reach two solar masses. In fact, neutron stars are star remnants, a kind of stellar zombies (they die, but do not disappear). In the last decades, astronomical observations yielded various contraints for the neutron star masses and finally, in 2017, a gravitational wave was detected (GW170817). Its source was identified as the merger of two neutron stars coming from NGC 4993, a galaxy 140 million light years away from us. The very same event was detected in γ-ray, x-ray, UV, IR, radio frequency and even in the optical region of the electromagnetic spectrum, starting the new era of multi-messenger astronomy. To understand and describe neutron stars, an appropriate equation of state that satisfies bulk nuclear matter properties is necessary. GW170817 detection contributed with extra constraints to determine it. On the other hand, magnetars are the same sort of compact objects, but bearing much stronger magnetic fields that can reach up to 10^15 G on the surface as compared with the usual 10^12 G present in ordinary pulsars. While the description of ordinary pulsars is not completely established, describing magnetars poses extra challenges. In this paper, I give an overview on the history of neutron stars and on the development of nuclear models and show how the description of the tiny world of the nuclear physics can help the understanding of the cosmos, especially of the neutron 

                                  a. binaries    b. stars   c. levels      d. pulsars.

Q104. arXiv:2106.12596 [astro-ph.GA]: Wed, 23 Jun 2021 18:00:05 UTC (9,184 KB): [Submitted on 23 Jun 2021]: Alignment of the magnetic field in star forming regions and why it might be difficult to observe. Philipp Girichidis. :ABSTRACT: Magnetic fields are an important component of the interstellar medium (ISM) and exhibit strongly varying field strengths and a non-trivial correlation with the gas density. Its dynamical impact varies between individual regions of the ISM and correlates with the orientation of the field with respect to the gas structures. Using high-resolution magneto-hydrodynamical simulations of the ISM we explore the connection between the orientation of the field and the dynamical state of the gas. We find that the onset of gravitational instability in molecular gas above a density of ρ∼10^−21gcm^−3 (n∼400cm^−3) coincides with an alignment of the magnetic field lines and the gas flow. At this transition the gradient of the density changes from mainly perpendicular to preferentially parallel to the field lines. A connection between the three-dimensional alignment and projected two-dimensional observables is non-trivial, because of a large dispersion of the magnetic field orientation along the line of sight. The turbulent correlation lengths can be small compared to the typical integration lengths. As a consequence the small scale signal of the orientation can sensitively depend on the line of sight or the dynamical state of the cloud, can fluctuate stochastically or be completely averaged out. With higher spatial resolution more small scale structures are resolved, which aggravates the link between magneto-hydrodynamical quantities and projected 

                                a. fields      b. signals    c.  dispersion    d. observables.

Q105.arXiv:2107.07447 [astro-ph.SR]: Thu, 15 Jul 2021 16:50:48 UTC (1,488 KB)[Submitted on 15 Jul 2021]: The Effect of Continuum Elimination in Identifying Circumstellar Dust around Mira. Lisa M. Shepard, Angela K. Speck. ABSTRACT: Asymptotic Giant Branch (AGB) stars are major contributors of cosmic dust to the universe. Typically, dust around AGB stars is investigated via radiative transfer (RT) modeling, or via simple deconstruction of observed spectra. However, methodologies applied vary. Using archival spectroscopic, photometric, and temporal data for the archetypal dusty star, Mira, we identify its circumstellar silicate dust grains. This is achieved by matching the positions and widths of observed spectral features with laboratory data. To do this comparison properly, it is necessary to account for the continuum emission. Here we investigate various ways in which a continuum is eliminated from observational spectra and how it affects the interpretation of spectral features. We find that while the precise continuum shapes and temperatures do not have a critical impact on the positions and shapes of dust spectral features, it is important to eliminate continua in a specific way. It is important to understand what contributes to the spectrum in order to remove the continuum in a way that allows comparison with laboratory spectra of candidate dust species. Our methodologies are applicable to optically thin systems, like that of Mira. Higher optical depths will require RT modeling, which cannot include many different potential astrominerals because there is a lack of complex refractive indices. Finally, we found that the classic silicate feature exhibited by Mira is not consistent with a real amorphous silicate alone but may be best explained with a small alumina contribution to match the observed FWHM of the 10 micron 

                                  a. feature    b. data     c. possibility     d. consistent.

Q106. arXiv:2107.06910 [hep-th]:  Wed, 14 Jul 2021 18:00:14 UTC (42 KB): [Submitted on 14 Jul 2021]: Universal signature of quantum entanglement across cosmological distances. Suddhasattwa Brahma, Arjun Berera, Jaime Calderón-Figueroa. ABSTRACT: Although the paradigm of inflation has been extensively studied to demonstrate how macroscopic inhomogeneities in our universe originate from quantum fluctuations, most of the established literature ignores the crucial role that entanglement between the modes of the fluctuating field plays in its observable predictions. In this paper, we import techniques from quantum information theory to reveal hitherto undiscovered predictions for inflation which, in turn, signals how quantum entanglement across cosmological scales can affect large scale structure. Our key insight is that observable long-wavelength modes must be part of an open quantum system, so that the quantum fluctuations can decohere in the presence of an environment of short-wavelength modes. By assuming the simplest model of single-field inflation, and considering the leading order interaction term from the gravitational action, we derive a universal lower bound on the observable effect of such inescapable 

                       a. separation    b. modes    c. entanglement     d. fluctuation.

Q107. arXiv:2107.07399 [hep-ph]: Thu, 15 Jul 2021 15:30:08 UTC (3,875 KB)[Submitted on 15 Jul 2021]: Axion-photon conversion in strongly magnetised plasmas. Alexander J. Millar, Sebastian Baum, Matthew Lawson, David M.C. Marsh:ABSTRACT: Axion dark matter can resonantly convert to photons in the magnetosphere of neutron stars, possibly giving rise to radio signals observable on Earth. This method for the indirect detection of axion dark matter has recently received significant attention in the literature. The calculation of the radio signal is complicated by a number of effects; most importantly, the gravitational infall of the axions onto the neutron star accelerates them to semi-relativistic speed, and the neutron star magnetosphere is highly anisotropic. Both of these factors complicate the calculation of the conversion of axions to photons. In this work, we present the first fully three-dimensional calculation of the axion-photon conversion in highly magnetised anisotropic media. Depending on the axion trajectory, this calculation leads to orders-of-magnitude differences in the conversion compared to the simplified one-dimensional calculation used so far in the literature, altering the directionality of the produced photons. Our results will have important implications for the radio signal one would observe in a 

                a. telescope     b. conversion    c. trajectory     d. calculation.

Q108. arXiv:2107.08333 [physics.optics]: Sun, 18 Jul 2021 00:50:09 UTC (6,245 KB): [Submitted on 18 Jul 2021]: Mid-Infrared Cross-Comb Spectroscopy. Mingchen Liu, Robert M. Gray, Arkadev Roy, Charles R. Markus, Alireza Marandi:ABSTRACT: Dual-comb spectroscopy has been proven a powerful tool in molecular characterization, which remains challenging to implement in the mid-infrared (MIR) region due to difficulties in the realization of two mutually locked comb sources and efficient photodetection. An effective way to overcome those limitations is optical upconversion; however, previously reported configurations are either demanding or inefficient. Here we introduce and experimentally demonstrate a variant of dual-comb spectroscopy called cross-comb spectroscopy, in which a MIR comb is upconverted via sum-frequency generation (SFG) with a near-infrared (NIR) comb with a shifted repetition rate and then interfered with a spectral extension of the NIR comb. We experimentally demonstrate a proof-of-concept measurement of atmospheric CO2 around 4.25 micrometer, with a 350-nm instantaneous bandwidth and 25000 resolved comb lines. Cross-comb spectroscopy can be realized using up- or down-conversion and offers an adaptable and efficient alternative to dual-comb spectroscopy outside the well-developed near-IR region, where having two mutually coherent sources and efficient photodetection is challenging. Moreover, the nonlinear gating in cross-comb spectroscopy promises a superior dynamic range compared to dual-comb 

                         a. band width   b. conversion   c. spectroscopy     d. adaptability. 

Q109. arXiv:2107.08703 [astro-ph.GA]:  Mon, 19 Jul 2021 09:24:53 UTC (7,711 KB): [Submitted on 19 Jul 2021]: The Nature of Hyperluminous Infrared Galaxies. F. Gao, L. Wang, A. Efstathiou, K. Małek, P. N. Best, M. Bonato, D. Farrah, R. Kondapally, I. McCheyne, H. J. A. Röttgering. ABSTRACT: We make use of multi-wavelength data of a large hyperluminous infrared (HLIRG) sample to derive their main physical properties, e.g., stellar mass, star-formation rate (SFR), volume density, contribution to the cosmic stellar mass density and to the cosmic SFR density. We also study the black hole (BH) growth rate and its relationship with the SFR of the host galaxy. We select 526 HLIRGs in three deep fields (Boötes, Lockman-Hole, ELAIS-N1) and adopt two spectral energy distribution (SED) fitting codes, CIGALE, which assumes energy balance, and CYGNUS, which is based on radiative transfer models and does not adopt energy balance principle. We use two different active galactic nucleus (AGN) models in CIGALE and three AGN models in CYGNUS to compare the results estimated using different SED fitting codes and different AGN models. The stellar mass, total IR luminosity and AGN luminosity agree well between different models with a typical median offset of 0.1 dex. The SFR estimates show the largest dispersions (up to 0.5 dex). This dispersion has an impact on the subsequent analysis, which may suggest that previous contradictory results could partly be due to different choices of methods. HLIRGs are ultra-massive galaxies with 99% of them having stellar masses larger than 10^11M⊙. Our results reveal a higher space density of ultra-massive galaxies than found in previous surveys or predicted by simulations. We find that HLIRGs contribute more to the cosmic SFR density as redshift increases. In terms of BH growth, the two SED fitting methods provide different results. We can see a clear trend in which SFR decreases as AGN luminosity increases when using CYGNUS estimates, possibly implying quenching by AGN, while this trend is much weaker when using CIGALE estimates. This difference is also influenced by the dispersion between SlFR estimates obtained by the two 

                                      a. methods    b. galaxies     c.  masses   d. codes.

Q110. arXiv:2107.09000 [astro-ph.CO]: Mon, 19 Jul 2021 16:23:17 UTC (136 KB):[Submitted on 19 Jul 2021]: Intrinsic and extrinsic gravitational flexions. Eileen Sophie Giesel, Basundhara Ghosh, Bjoern Malte Schaefer. :ABSTRACT: The topic of this paper is a generalisation of the linear model for intrinsic alignments of galaxies to intrinsic flexions: In this model, third moments of the brightness distribution reflect distortions of elliptical galaxies caused by third derivatives of the gravitational potential, or, equivalently, gradients of the tidal gravitational fields. With this extension of the linear model mediating between the brightness distribution and the tidal gravitational fields and with a quantification of the shape of the galaxy at third order provided by the HOLICs-formalism, we are able to compute angular spectra of intrinsic flexions and the cross-spectra with weak lensing flexions. Spectra for intrinsic flexions are typically an order of magnitude smaller than lensing flexions, exactly as in the case of intrinsic ellipticity in comparison to weak shear. We find a negative cross correlation between intrinsic and extrinsic gravitational flexions, too, complementing the analogous correlation between intrinsic and extrinsic ellipticity. After discussing the physical details of the alignment model to provide intrinsic flexions and their scaling properties, we quantify the observability of the intrinsic and extrinsic flexions and estimate with the Fisher-formalism how well the alignment parameter can be determined from a Euclid-like weak lensing survey. Intrinsic flexions are very difficult to measure and yield appreciable signals only with optimistic parameter choices, even for a survey like

                        a. Einstein    b. Euclid      c. Sommerfeld     d. K R Rao.

Q111. arXiv:2107.09567 [astro-ph.SR]: Tue, 20 Jul 2021 15:29:24 UTC (92 KB): [Submitted on 20 Jul 2021]: SiO masers and 7 mm Continuum in Mira and R Aqr. W. D. Cotton, E. Humphreys, M. Wittkowski, A. Baudry, A. M. S. Richards, W. Vlemmings, T. Khouri, S. Etoka. :ABSTRACT: Interactions between AGB stars and a secondary in a close orbit are one possible explanation of why some AGB stars develop into aspherical planetary nebulae. This study uses millimeter observations of the continuum and SiO maser emission in several symbiotic Miras looking for evidence of an interaction between the two stars. New JVLA observations at ~45 mas resolution are analyzed, imaging continuum and SiO masers. Two of the three targets were detected and accurately registered continuum and line images were derived. No clear evidence of an interaction was found between components B and A in Mira. R Aqr has a well known jet arising from the secondary star. The jet may be disturbing the circumstellar envelop of the AGB star or possibly just nearly aligned with

                                a. them   b. SiO     c. Masers     d. it.

Q112.arXiv:2107.09585 [astro-ph.GA]: Tue, 20 Jul 2021 16:00:34 UTC (1,394 KB): [Submitted on 20 Jul 2021]>: The Far Ultraviolet Background. S. R. Kulkarni. :ABSTRACT: The diffuse far-ultraviolet (FUV) background has received considerable attention from astronomers since the seventies. The initial impetus came from the hope of detecting UV radiation from the hot intergalactic medium. The central importance of the FUV background to the physics (heating and ionization) of the diffuse atomic phases motivated the next generation of experiments. The consensus view is that the diffuse FUV emission at high latitudes has three components: stellar FUV reflected by dust grains (diffuse galactic light or DGL), FUV from other galaxies (extra-galactic background light, EBL) and a component of unknown origin. During the eighties, there was some discussion that decaying dark matter particles produced FUV radiation. In this paper I investigate production of FUV photons by conventional sources: the Galactic Hot Ionized Medium (line emission), two photon emission from the Galactic Warm Ionized Medium and low-velocity shocks, and Lyman-beta excitation of hydrogen at several locales in the Solar System (the interplanetary medium, the exosphere and thermosphere of Earth). I conclude that two thirds of the third component can be explained by the sum of the processes listed 

                         a. above.   b. primarily    c. accidentally     d. positively.

Q113. arXiv:2107.07399 [hep-ph]: [v1] Thu, 15 Jul 2021 15:30:08 UTC (3,875 KB): [v2] Fri, 16 Jul 2021 08:15:06 UTC (3,875 KB): [Submitted on 15 Jul 2021 (v1), last revised 16 Jul 2021 (this version, v2)]: Axion-photon conversion in strongly magnetised plasmas. Alexander J. Millar, Sebastian Baum, Matthew Lawson, M.C. David Marsh. ABSTRACT: Axion dark matter can resonantly convert to photons in the magnetosphere of neutron stars, possibly giving rise to radio signals observable on Earth. This method for the indirect detection of axion dark matter has recently received significant attention in the literature. The calculation of the radio signal is complicated by a number of effects; most importantly, the gravitational infall of the axions onto the neutron star accelerates them to semi-relativistic speed, and the neutron star magnetosphere is highly anisotropic. Both of these factors complicate the calculation of the conversion of axions to photons. In this work, we present the first fully three-dimensional calculation of the axion-photon conversion in highly magnetised anisotropic media. Depending on the axion trajectory, this calculation leads to orders-of-magnitude differences in the conversion compared to the simplified one-dimensional calculation used so far in the literature, altering the directionality of the produced photons. Our results will have important implications for the radio signal one would observe in a

                             a. signal   b.  media    c. telescope    d. microscope 

Q114. arXiv:2108.07287 [astro-ph.GA]: [v1] Mon, 16 Aug 2021 18:00:23 UTC (7,329 KB): [Submitted on 16 Aug 2021]: Origin of the ring structures in Hercules A -- Sub-arcsecond 144 MHz to 7 GHz observations. R. Timmerman, et al., :ABSTRACT: The prominent radio source Hercules A features complex structures in its radio lobes. Although it is one of the most comprehensively studied sources in the radio sky, the origin of the ring structures in the Hercules A radio lobes remains an open question. We present the first sub-arcsecond angular resolution images at low frequencies (<300 MHz) of Hercules A, made with the International LOFAR Telescope. With the addition of data from the Karl G. Jansky Very Large Array, we mapped the structure of the lobes from 144 MHz to 7 GHz. We explore the origin of the rings within the lobes of Hercules A, and test whether their properties are best described by a shock model, where shock waves are produced by the jet propagating in the radio lobe, or by an inner-lobe model, where the rings are formed by decelerated jetted plasma. From spectral index mapping our large frequency coverage reveals that the curvature of the different ring spectra increases with distance away from the central active galactic nucleus. We demonstrate that the spectral shape of the rings is consistent with synchrotron aging, which speaks in favor of an inner-lobe model where the rings are formed from the deposition of material from past periods of intermittent core 

                                     a. frequency      b. activity     c. cover      d. mapping.

Q115. arXiv:2108.07461 [astro-ph.GA]: Tue, 17 Aug 2021 06:34:35 UTC (6,124 KB): bmitted on 17 Aug 2021]: A Spectroscopic Study of Supernova Remnants with the Infrared Space Observatory. Authors: Matthew J. Millard, Aravind P. Ravi, Jeonghee Rho, Sangwook Park. :ABSTRACT: We present far-infrared (FIR) spectroscopy of supernova remnants (SNRs) based on the archival data of the Infrared Space Observatory (ISO) taken with the Long Wavelength Spectrometer (LWS). Our sample includes previously unpublished profiles of line and continuum spectra for 20 SNRs in the Galaxy and Magellanic Clouds. In several SNRs including G21.5-0.9, G29.7-0.3, the Crab Nebula, and G320.4-1.2, we find evidence for broad [O I], [O III], [N II], and [C II] lines with velocity dispersions up to a few 10^3 km s^−1, indicating that they are associated with high-velocity SN ejecta. Our detection of Doppler-broadened atomic emission lines and a bright FIR continuum hints at the presence of newly formed dust in SN ejecta. For G320.4-1.2, we present the first estimate of an ejecta-dust mass of 0.1 - 0.2 M⊙, which spatially coincides with the broad line emission, by applying a blackbody model fit with components of the SNR and background emission. Our sample includes raster maps of 63, 145 μm [O I] and 158 μm [C II] lines toward SNRs Kes 79, CTB 109, and IC 443. Based on these line intensities, we suggest interacting shock types in these SNRs. Finally, we compare our LWS spectra of our sample SNRs with the spectra of several HII regions, and discuss their FIR line intensity ratios and continuum properties. Follow-up observations with modern instruments (e.g. JWST and SOFIA) with higher spatial and spectral resolution are encouraged for an extensive study of the SN ejecta and the SN 

                                      a. sample   b. spectra    c.  intensity      d. dust.

Q116. arXiv:2108.08341 [astro-ph.HE]: Wed, 18 Aug 2021 18:33:04 UTC (2,180 KB)[Submitted on 18 Aug 2021]: Update on the Combined Analysis of Muon Measurements from Nine Air Shower Experiment. Dennis Soldin (for the EAS-MSU, IceCube, KASCADE-Grande, NEVOD-DECOR, Pierre Auger, SUGAR, Telescope Array, and Yakutsk EAS Array Collaborations)lABSTRACT:  Over the last two decades, various experiments have measured muon densities in extensive air showers over several orders of magnitude in primary energy. While some experiments observed differences in the muon densities between simulated and experimentally measured air showers, others reported no discrepancies. We will present an update of the meta-analysis of muon measurements from nine air shower experiments, covering shower energies between a few PeV and tens of EeV and muon threshold energies from a few 100 MeV to about 10 GeV. In order to compare measurements from different experiments, their energy scale was cross-calibrated and the experimental data has been compared using a universal reference scale based on air shower simulations. Above 10 PeV, we find a muon excess with respect to simulations for all hadronic interaction models, which is increasing with shower energy. For EPOS-LHC and QGSJet-II.04 the significance of the slope of the increase is analyzed in detail under different assumptions of the individual experimental

                          a. uncertanities    b. unresolved    c. unaccounted  d. unknown

Q117. arXiv:2108.08425 [astro-ph.HE]:  Thu, 19 Aug 2021 01:17:30 UTC (110 KB)[Submitted on 19 Aug 2021]: Pre-burst neutrinos of gamma-ray bursters accompanied by high-energy photons, Jie Zhu, Bo-Qiang Ma. :ABSTRACT: Previous researches on high-energy neutrino events from gamma-ray bursters (GRBs) suggest a neutrino speed variation v(E)=c(1±E/EνLV) with EνLV=(6.4±1.5)×10^17 GeV, together with an intrinsic time difference Δtin=(−2.8±0.7)×10^2 s, which means that high-energy neutrinos come out about 300~s earlier than low-energy photons in the source reference system. Considering the possibility that pre-bursts of neutrinos may be accompanied by high-energy photons, in this work we search for high-energy photon events with earlier emission time from 100 to 1000~s before low-energy photons at source by analyzing Fermi Gamma-ray Space Telescope (FGST) data. We perform the searching of photon events with energies larger than 100~MeV, and find 14 events from 48 GRBs with known redshifts. Combining these events with a 1.07 TeV photon event observed by the Major Atmospheric Gamma Imaging Cherenkov telescopes (MAGIC), we suggest a pre-burst stage with a long duration period of several minutes of high energy neutrino emissions accompanied by high energy photons at the GRB 

                                    a. data   b. extent    c. source   d. field.

Q118. arXiv:2108.08472 [physics.app-ph]: Thu, 19 Aug 2021 03:28:37 UTC (1,356 KB) [Submitted on 19 Aug 2021]: Transfer Matrix description of heterostructured spintronics Terahertz emission. Authors: Yingshu Yang, Stefano Dal Forno, Marco Battiato. :ABSTRACT: In this work we developed an extension to the Transfer Matrix method (TMM) to include a current source term, with the aim of describing both the transmission and emission of THz pulses in spintronics THz emitters.The terahertz (THz) frequency gap is a frequency range between infrared and microwaves (0.1–10 THz). This frequency range is drawing much attention in a number of fields aimed at the fabrication of new optoelectronic devices. The TMM with source is derived from the Maxwell equations with a volume free current term. This extension to the TMM allows for the study of realistic spintronics THz emitters as multilayers of different materials with different thicknesses. We use this to prove that, in spite of a common misconception, the drop rate of the THz emission amplitude at higher heavy metal layer thicknesses is not related and does not provide information about the spin diffusion length. It is instead the effect of the increase in the parasitic absorption of the generated radiation by the conducting parts of the spintronics THz emitter 

                          a. itself       b. current      c. description     d. term.

Q119. arXiv:2108.08747 [physics.app-ph]: Thu, 19 Aug 2021 15:21:41 UTC (7,047 KB): [Submitted on 19 Aug 2021]: Printable, castable, nanocrystalline cellulose-epoxy composites exhibiting hierarchical nacre-like toughening. Authors: Abhinav Rao, Thibaut Divoux, Crystal Owens, A. John Hart. ABSTRACT: Due to their exceptional mechanical and chemical properties and their natural abundance, cellulose nanocrystals (CNCs) are promising building blocks of sustainable polymer composites. However, the rapid gelation of CNC dispersions has generally limited CNC-based composites to low CNC fractions, in which polymer remains the dominant phase. Here we report on the formulation and processing of crosslinked CNC-epoxy composites with a CNC fraction exceeding 50 wt.%. The microstructure comprises sub-micrometer aggregates of CNCs crosslinked to polymer, which are analogous to the lamellar structure of nacre and promotes toughening mechanisms associated with bulk ductile behavior, despite the brittle behavior of the aggregates at the nanoscale. At 63 wt.% CNCs, the composites exhibit a hardness of 0.66 GPa and a fracture toughness of 5.2 MPa.m[Math Processing Error]. The hardness of this all-organic material is comparable to aluminum alloys, and the fracture toughness at the centimeter scale is comparable to that of wood cell wall. We show that CNC-epoxy composite objects can be shaped from the gel precursors by direct-write printing and by casting, while the cured composites can be machined into complex 3D shapes. The formulation, processing route, and the insights on toughening mechanisms gained from our multiscale approach can be applied broadly to highly loaded 

                  a. composits     b. shapes    c.  nanocomposits     d. castings.

Q120.arXiv:2109.01678 [astro-ph.CO]:Fri, 3 Sep 2021 18:00:03 UTC (440 KB):  [Submitted on 3 Sep 2021]: Title: Connecting the Extremes: A Story of Supermassive Black Holes and Ultralight Dark Matter. Authors: Hooman Davoudiasl, Peter B. Denton, Julia Gehrlein.: ABSTRACT: The formation of ultra rare supermassive black holes (SMBHs), with masses of O(10^9M⊙), in the first billion years of the Universe remains an open question in astrophysics. At the same time, ultralight dark matter (DM) with mass in the vicinity of O(10^−20 eV) has been motivated by small scale DM distributions. Though this type of DM is constrained by various astrophysical considerations, certain observations could be pointing to modest evidence for it. We present a model with a confining first order phase transition at ∼10 keV temperatures, facilitating production of O(10^9M⊙) primordial SMBHs. Such a phase transition can also naturally lead to the implied mass for a motivated ultralight axion DM candidate, suggesting that SMBHs and ultralight DM may be two sides of the same cosmic coin. We consider constraints and avenues to discovery from superradiance and a modification to Neff. On general grounds, we also expect primordial gravitational waves -- from the assumed first order phase transition -- characterized by frequencies of O(10^−12−10^−9 Hz). This frequency regime is largely uncharted, but could be accessible to pulsar timing arrays if the primordial gravitational waves are at the higher end of this frequency range, as could be the case in our assumed confining phase 

                           a. transition    b.  uncharted   c. avenues   d. grounds.

Q121: arXiv:2109.01833 [astro-ph.SR]: Sat, 4 Sep 2021 09:59:48 UTC (4,038 KB): [Submitted on 4 Sep 2021]:Title: Theory of magnetic flux tubes in strong fields and the phenomenon of dark matter axions identical to solar axions. Authors: Vitaliy D. Rusov, Vladimir P. Smolyar, Margarita E. Beglaryan. :ABSTRACT: We develop the general laws of the theory of the almost empty anchored magnetic flux tubes (MFT) with B~10^7G, starting from tachocline to the surface of the Sun. The main result of this theory is the formation of the solar axions and the magnetic O-loop inside the MFT near the tachocline. In this magnetic O-loop (based on the Kolmogorov turbulent cascade) the axions are converted to photons, producing the axion origin photons near the tachocline. On the other hand, high-energy photons from the radiation zone through the axion-photon oscillations in the O-loop produce the axions of photon origin under the sunspot. This means that at such strong magnetic fields the Parker-Biermann cooling effect of MFT develops due to the "disappearance" of the Parker's convective heat transport, and consequently, the temperature in the lower part of the magnetic tube with the help of the axions of photonic origin near the tachocline. As a result, a free path for photons of axion origin opens from the tachocline to the photosphere!. We show that the high-energy photons passing from the radiation zone turn into axions, which almost completely eliminates the radiation heating of the almost empty MFT. A certain flux of photons coming from the radiation zone through the tachocline, passes through the "ring" of a strong magnetic tube by virtue of convective heating. It allows to determine the velocity and the lifetime of the MFT before the reconnection, from tachocline to the surface of the Sun, as well as the rate of the MFT reconnection near the tachocline. Finally, we show that the formation of sunspot cycles is is the manifestation of dark matter -- solar axions in the core of the Sun, whose modulations are controlled by the 11-year modulation of asymmetric dark matter density in the solar 

                                   a.    exterior     b. interior      c. photons      d.  tachocline.

Q122. arXiv:2109.02574 [cond-mat.mtrl-sci]:  Mon, 6 Sep 2021 16:20:15 UTC (945 KB): [Submitted on 6 Sep 2021]: Title: In-plane electric field induced exciton dissociation in two dimensional transition metal dichalcogenides. Authors:  Lei Xu, Tao Zhu. :ABSTRACT: We present a theoretical study of the in-plane electric filed induced exciton dissociation in two dimensional (2D) transition metal dichcogenides MX2 (M=Mo, W; X=S, Se). The exciton resonance states are determined from continuum states by the complex coordinate rotation method with the Lagrange mesh method to solve the exciton Hamiltonian. Our results show that the exciton dissociation process can be effectively controlled by the electric field. The critical electric fields needed for ground state exciton to make the dissociation process dominating over combination processes is in the range of 73 - 91 V/μm for monolayer MX2. Compared with ground state exciton, the excited excitons are more easily to be dissociated due to their delocalization nature, e.g. the critical field for 2s excited state is as low as 12 - 16 V/μm . More importantly, we found that exciton become more susceptive to external electric field and a much smaller critical electric field is needed in the presence of a dielectric substrate and in finite-layer MX2. This work may provide a promising way to enhance the exciton dissociation process and improve the performance of 2D materials based optoelectronic 

                                        a. junctions     b. circuits    c. works    d. devices.

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Answers: TRUWIZ122b. Dated. September 09, 2021. 

Q62.a,Q63.c,Q64.b,Q65.d,Q66.c,Q67.a,Q68.d,Q69.b,Q70.a,Q71.c,Q72.b,Q73.a,Q74.d, Q75.b,Q77.c,Q78.b,Q79.a,Q80.c,Q81.a,Q82.c,Q83.b,Q84.c,Q85.b,Q86.d,Q87.b,Q88.c,

Q89.a,Q90.b,Q91.d,Q92.c,Q93.a,Q94.b,Q95.d,Q96.a,Q97.c,Q98.b,Q99.d,Q100.b,

Q101.a,Q102.c,Q103.b,Q104.d,Q105.a,Q106.c,Q107.a,Q108.c,Q109.d,Q110.b,Q111.d,

Q112.a,Q113.c,Q114.b,Q115.d,Q115.a,Q117.c,Q118.a,Q119.c,Q120.a,Q121.b,Q122.d. 

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