Miracle-dz/UniFAR-FTUs huggingface dataset:
Connecting processes with indefinite causal order and multi-time quantum states

Recently, the possible existence of quantum processes with indefinite causal order has been extensively discussed, in particular using the formalism of process matrices. Here we give a new perspective on this question, by establishing a direct connection to the theory of multi-time quantum states. Specifically, we show that process matrices are equivalent to a particular class of pre- and post-selected quantum states. This offers a new conceptual point of view to the nature of process matrices. Our results also provide an explicit recipe to experimentally implement any process matrix in a probabilistic way, and allow us to generalize some of the previously known properties of process matrices. Finally we raise the issue of the difference between the notions of indefinite temporal order and indefinite causal order, and show that one can have indefinite causal order even with definite temporal order.
Strain effects on the band gap and optical properties of perovskite SrSnO3 and BaSnO3

We report calculations of the band gaps and optical spectra of perovskite BaSnO3 and SrSnO3 as a function of strain. We find that the behavior of these compounds is controlled almost entirely by the volumetric strain and in particular that unlike commonly studied transition metal based perovskites, there is little sensitivity to strains other than volumetric. The most effective tuning parameters for the gap and optical properties of stannate perovskites are composition (A-site alloying) and volumetric strain.
Moments of inertia, nucleon axial-vector coupling, the 8, 10, , and 273/2, and 273/2 mass spectra and the higher SU(3)f representation mass splittings in the Skyrme model

The broad importance of a recent experimental discovery of pentaquarks re- quires more theoretical insight into the structure of higher representation multiplets. The nucleon axial-vector coupling, moments of inertia, the 8, 10, 10, and 273=2 absolute mass spectra and the higher SU(3)f representation mass splittings for the multiplets 8, 10, 10, 27, 35, 35, and 64 are computed in the framework of the minimal SU(3)f extended Skyrme model by using only one free parameter, i.e., the Skyrme charge e. The analysis presented in this paper represents simple and clear theoretical estimates, obtained without using any experimental results for higher (10,.) multiplets. The obtained results are in good agreement with other chiral soliton model approaches that more extensively use experimental results as inputs.
Gauge/gravity duality and meta-stable dynamical supersymmetry breaking

We engineer a class of quiver gauge theories with several interesting features by studying D-branes at a simple Calabi-Yau singularity. At weak 't Hooft coupling we argue using field theory techniques that these theories admit both supersymmetric vacua and meta-stable non-supersymmetric vacua, though the arguments indicating the existence of the supersymmetry breaking states are not decisive. At strong 't Hooft coupling we find simple candidate gravity dual descriptions for both sets of vacua.
Inherent thermal convection in a granular gas inside a box under a gravity field

We theoretically prove the existence in granular fluids of a thermal convection that is inherent in the sense that it is always present and has no thermal gradient threshold (convection occurs for all finite values of the Rayleigh number). More specifically, we study a gas of inelastic smooth hard disks enclosed in a rectangular region under a constant gravity field. The vertical walls act as energy sinks (i.e. inelastic walls that are parallel to gravity), whereas the other two walls are perpendicular to gravity and act as energy sources. We show that this convection is due to the combined action of dissipative lateral walls and a volume force (in this case, gravitation). Hence, we call it dissipative lateral walls convection (DLWC). Our theory, which also describes the limit case of elastic collisions, shows that inelastic particle collisions enhance the DLWC. We perform our study via numerical solutions (volume-element method) of the corresponding hydrodynamic equations in an extended Boussinesq approximation. We show that our theory describes the essentials of the results for similar (but more complex) laboratory experiments.
Black hole genesis of dark matter

We present a purely gravitational infra-red-calculable production mechanism for dark matter (DM) . The source of both the DM relic abundance and the hot Standard Model (SM) plasma is a primordial density of micro black holes (BHs), which evaporate via Hawking emission into both the dark and SM sectors. The mechanism has four qualitatively different regimes depending upon whether the BH evaporation is 'fast' or 'slow' relative to the initial Hubble rate, and whether the mass of the DM particle is 'light' or 'heavy' compared to the initial BH temperature. For each of these regimes we calculate the DM yield, Y, as a function of the initial state and DM mass and spin. In the 'slow' regime Y depends on only the initial BH mass over a wide range of initial conditions, including scenarios where the BHs are a small fraction of the initial energy density. The DM is produced with a highly non-thermal energy spectrum, leading in the 'light' DM mass regime (~260 eV and above depending on DM spin) to a strong constraint from free-streaming, but also possible observational signatures in structure formation in the spin 3/2 and 2 cases. The 'heavy' regime (~1.2 × 108 GeV to MPl depending on spin) is free of these constraints and provides new possibilities for DM detection. In all cases there is a dark radiation component predicted.
Joint gravitational wave - gamma-ray burst detection rates in the aftermath of GW170817

The observational follow-up campaign of the gravitational wave (GW) multimessenger event GW170817/GRB170817A has shown that the prompt gamma-rays are consistent with a relativistic structured jet observed from a wide viewing angle ≳20°. We perform Bayesian inference using the data from early and late EM observations to determine the jet profile of GRB170817A assuming a structured jet model. We use the geometric dependence on the burst luminosity to produce a short-duration gamma-ray burst (sGRB) efficiency function with redshift, which folded in with binary neutron star detection rate, allows us to estimate the future joint GW/sGRB detection rates for LIGO and Virgo detectors. We show that if the jet structured profile of GRB170817A is a relatively common feature of sGRBs, then there is a realistic probability of another off-axis coincident detection during the third aLIGO/Virgo observing run (O3). We also find that up to 4 yr−1 joint events may be observed during the advanced LIGO run at design sensitivity and up to 10 yr−1 by the upgraded advanced LIGO configuration A+. We show that the detection efficiencies for wide-angled sGRB emissions will be limited by GRB satellites as the GW detection range increases through proposed upgrades. Therefore, although the number of coincident detections will increase with GW detector sensitivity, the relative proportion of detected binary neutron stars with gamma-ray counterparts will decrease; 11 per cent for O3 down to 2 per cent during A+.
Effects of Combustion on the Sound Pressure Generated by Circular Jet Flows

5Kim, J. W. , and Lee, D. J., “Optimized Compact Finite Difference Schemes with Maximum Resolution,” AIAA Journal, Vol. 34, No. 5, 1996, pp. 887–893. 6Kim, J. W. , and Lee, D. J., “Adaptive Nonlinear Arti cial Dissipation Model for Computational Aeroacoustics,” AIAA Journal, Vol. 39, No. 5, 2001, pp. 810–818. 7Whitham, G. B. , Linear and NonlinearWaves, Wiley, New York, 1974. 8Thomson,K.W. , “TimeDependentBoundaryConditionsforHyperbolic Systems,” Journalof ComputationalPhysics, Vol. 68,No. 1, 1987,pp. 1–24.
Crossed Andreev reflection in structures consisting of a superconductor with ferromagnetic leads

A theory of crossed Andreev reflection in structures consisting of a superconductor with two ferromagnetic leads is presented. The electric current due to the crossed Andreev reflection strongly depends on the relative orientation of the magnetization of two ferromagnetic leads. It is shown that the dependence of the electric current and magnetoresistance on the distance between two ferromagnetic leads is understood by considering the interference between the wave functions in ferromagnets. The current and magnetoresistance are calculated as functions of the exchange field and height of the interfacial barriers.
Collective Effects in Nanolasers Explained by Generalized Rate Equations

We study the stationary photon output and statistics of small lasers. Our closed-form expressions clarify the contribution of collective effects due to the interaction between quantum emitters. We generalize laser rate equations and explain photon trapping: a decrease of the photon number output below the lasing threshold, derive an expression for the stationary cavity mode autocorrelation function $g_2$, which implies that collective effects may strongly influence the photon statistics. We identify conditions for coherent, thermal and superthermal radiation, the latter being a unique fingerprint for collective emission in lasers. These generic analytical results agree with recent experiments, complement numerical results, and provide insight into and design rules for nanolasers.
Ultra-bright CO and [ ] Emission in a Lensed z = 2.04 Submillimeter Galaxy with Extreme Molecular Gas Properties

We report the very bright detection of cold molecular gas with the IRAM NOEMA interferometer of the strongly lensed source WISE J132934.18+224327.3 at z = 2.04, the so-called Cosmic Eyebrow. This source has a similar spectral energy distribution from optical-mid/IR to submillimeter/radio but significantly higher fluxes than the well-known lensed SMG SMMJ 2135, the Cosmic Eyelash at z = 2.3. The interferometric observations unambiguously identify the location of the molecular line emission in two components, component CO32-A with Jy km s−1 and component CO32-B with Jy km s−1. Thus, our NOEMA observations of the CO(3−2) transition confirm the SMG-nature of WISE J132934.18+224327.3, resulting in the brightest CO(3−2) detection ever of an SMG. In addition, we present follow-up observations of the brighter component with the Green Bank Telescope (CO(1−0) transition) and IRAM 30 m telescope (CO(4−3) and [C i](1−0) transitions). The star formation efficiency of ∼100 L☉/(K km s−1 pc2) is at the overlap region between merger-triggered and disk-like star formation activity and the lowest seen for lensed dusty star-forming galaxies. The determined gas depletion time ∼60 Myr, intrinsic infrared star formation SFRIR ≈ 2000 M⊙ yr−1, and gas fraction Mmol/M* = 0.44 indicate a starburst/merger-triggered star formation. The obtained data of the cold ISM—from CO(1−0) and dust continuum—indicates a gas mass μMmol ∼ 15 × 1011 M☉ for component CO32-A. Its unseen brightness offers us the opportunity to establish the Cosmic Eyebrow as a new reference source at z = 2 for galaxy evolution.
Scalar Field Dark Matter: head-on interaction between two structures

Instituto de F´isica y Matem´aticas, Universidad Michoacana de San Nicol´as de Hidalgo. Ediﬁcio C-3,Cd. Universitaria, C. P. 58040 Morelia, Michoac´an, M´exico. (Dated: February 5, 2008)In this manuscript we track the evolution of a system consisting of two self-gravitating virializedobjects made of a scalar ﬁeld in the newtonian limit. The Schr¨odinger-Poisson system containsa potential with self-interaction of the Gross-Pitaevskii type for Bose Condensates. Our resultsindicate that solitonic behavior is allowed in the scalar ﬁeld dark matter model when the totalenergy of the system is positive, that is, the two blobs pass through each other as should happenfor solitons; on the other hand, there is a true collision of the two blobs when the total energy isnegative.
Electron Heating in Hot Accretion Flows

Local (shearing box) simulations of the nonlinear evolution of the magnetorotational instability in a collisionless plasma show that angular momentum transport by pressure anisotropy (p⊥ ≠ p∥, where the directions are defined with respect to the local magnetic field) is comparable to that due to the Maxwell and Reynolds stresses. Pressure anisotropy, which is effectively a large-scale viscosity, arises because of adiabatic invariants related to p⊥ and p∥ in a fluctuating magnetic field. In a collisionless plasma, the magnitude of the pressure anisotropy, and thus the viscosity, is determined by kinetic instabilities at the cyclotron frequency. Our simulations show that ~50% of the gravitational potential energy is directly converted into heat at large scales by the viscous stress (the remaining energy is lost to grid-scale numerical dissipation of kinetic and magnetic energy). We show that electrons receive a significant fraction [~(Te/Ti)1/2] of this dissipated energy. Employing this heating by an anisotropic viscous stress in one-dimensional models of radiatively inefficient accretion flows, we find that the radiative efficiency of the flow is greater than 0.5% for ≳ 10-4Edd. Thus, a low accretion rate, rather than just a low radiative efficiency, is necessary to explain the low luminosity of many accreting black holes. For Sgr A* in the Galactic center, our predicted radiative efficiencies imply an accretion rate of ≈3 × 10-8 M☉ yr-1 and an electron temperature of ≈3 × 1010 K at ≈10 Schwarzschild radii; the latter is consistent with the brightness temperature inferred from VLBI observations.
H-band discovery of additional second-generation stars in the Galactic bulge globular cluster NGC 6522 as observed by APOGEE and Gaia

We present an elemental abundance analysis of high-resolution spectra for five giant stars spatially located within the innermost regions of the bulge globular cluster NGC 6522 and derive Fe, Mg, Al, C, N, O, Si, and Ce abundances based on H-band spectra taken with the multi-object APOGEE-north spectrograph from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. Of the five cluster candidates, two previously unremarked stars are confirmed to have second-generation (SG) abundance patterns, with the basic pattern of depletion in C and Mg simultaneous with enrichment in N and Al as seen in other SG globular cluster populations at similar metallicity. In agreement with the most recent optical studies, the NGC 6522 stars analyzed exhibit (when available) only mild overabundances of the s-process element Ce, contradicting the idea that NGC 6522 stars are formed from gas enriched by spinstars and indicating that other stellar sources such as massive AGB stars could be the primary polluters of intra-cluster medium. The peculiar abundance signatures of SG stars have been observed in our data, confirming the presence of multiple generations of stars in NGC 6522.
Bow Ties in the Sky. II. Searching for Gamma-Ray Halos in the Fermi Sky Using Anisotropy

Many-degree-scale gamma-ray halos are expected to surround extragalactic high-energy gamma-ray sources. These arise from the inverse Compton emission of an intergalactic population of relativistic electron/positron pairs generated by the annihilation of gamma rays on the extragalactic background light. These are typically anisotropic due to the jetted structure from which they originate (in the case of radio galaxies) or are oriented perpendicular to a large-scale intergalactic magnetic field (for blazar geometries). Here, we propose a novel method for detecting these inverse Compton gamma-ray halos based on this anisotropic structure that is centered on the active galactic nucleus (AGN). By marginalizing over the radial distribution of halo photons, we demonstrate that the angular power spectrum shows a characteristic sawtooth pattern with a dominant dipolar power and elevated even multipoles. Specifically, we show that by stacking those angular power spectra instead of images, it is possible to robustly detect gamma-ray halos with existing Fermi Large Area Telescope (LAT) observations for a broad class of intergalactic magnetic fields. Importantly, by testing a large number of systematics, our suggested power spectrum statistics appears to be robust and unbiased with respect to systematic uncertainties within the LAT instrumental response and associated with contaminating astronomical sources.
Optical properties of the spin-ladder compound Sr 14 Cu 24 O 41

We report the measurements of the pseudodielectric function, far-infrared reflectivity, and Raman scattering spectra in ${\mathrm{Sr}}_{14}{\mathrm{Cu}}_{24}{\mathrm{O}}_{41}$ single crystal. We study the lattice and the spin dynamics of the ${\mathrm{Cu}}_{2}{\mathrm{O}}_{3}$ spin ladders and ${\mathrm{CuO}}_{2}$ chains of this compound. The ellipsometric and the optical reflectivity measurements yield the gap values of 1.4, 1.86, 2.34 eV (2.5 eV) for the ladders (chains) along the c axis and 2.4 eV along the a axis. The electronic structure of the ${\mathrm{Cu}}_{2}{\mathrm{O}}_{3}$ ladders is analyzed using the tight-binding approach for the correlated electron systems. The correlation gap value of 1.4 eV is calculated with the transfer energy (hopping) parameters ${t=t}_{0}=0.26\mathrm{eV},$ along and perpendicular to legs, ${t}_{\mathrm{xy}}=0.026\mathrm{eV}$ (interladder hopping) and $U=2.1\mathrm{eV},$ as a Coulomb repulsion. The optical parameters of the infrared-active phonons and plasmons are obtained by an oscillator fitting procedure of the reflectivity spectra. Raman scattering spectra are measured at different temperatures using different laser line energies. The two-magnon peak is observed at about 2880 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. At temperatures below 150 K the new infrared and Raman modes appear due to the charge ordering.
Disentangling the AGN and star formation connection using XMM-Newton

There is growing evidence supporting the coeval growth of galaxies and their resident super-massive black hole (SMBH). Most studies also claim a correlation between the activity of the SMBH and the star formation of the host galaxy. It is unclear, however, whether this correlation extends to all redshifts and X-ray luminosities. Some studies find a weaker dependence at lower luminosities and/or a suppression of the star formation at high luminosities. We here use data from the X-ATLAS and XMM-XXL North fields and compile the largest X-ray sample up to date to investigate how X-ray selected AGN affect the star formation of their host galaxies in a wide redshift and luminosity baseline of 0.03 < z < 3 and log LX(2−10 keV) = (41−45.5) erg s−1. Our sample consists of 3336 AGN. 1872 of our sources have spectroscopic redshifts. For the remaining sources we calculate photometric redshifts using TPZ, a machine-learning algorithm. We estimate stellar masses (M⋆) and star formation rates (SFRs) by applying spectral energy distribution fitting through the CIGALE code, using optical, near-IR, and mid-IR photometry (SDSS, VISTA, and WISE). Of our sources, 608 also have far-IR photometry (Herschel). We use these sources to calibrate the SFR calculations of our remaining X-ray sample. Our results show a correlation between the X-ray luminosity (LX) and the SFR of the host galaxy at all redshifts and luminosities spanned by our sample. We also find a dependence of the specific SFR (sSFR) on redshift, while there are indications that the X-ray luminosity enhances the sSFR even at low redshifts. We then disentangle the effects of stellar mass and redshift on the SFR and again study its dependence on the X-ray luminosity. Towards this end, we estimate the SFR of main-sequence galaxies that have the same stellar mass and redshift as our X-ray AGN and compare them with the SFR of our X-ray AGN. Our analysis reveals that the AGN enhances the star formation of its host galaxy when the galaxy lies below the main sequence and quenches the star formation of the galaxy it lives in when the host lies above the main sequence. Therefore, the effect of AGN on the SFR of the host galaxy depends on the location of the galaxy relative to the main sequence.
Spectral variability in early-type binary X-ray systems

Theoretical models for the ionization of trace elements in a strong stellar wind by a compact binary X-ray source and for the resulting orbital phase dependence of the emergent soft X-ray spectra and the profiles of ultraviolet resonance lines are presented. Model results agree qualitatively with the X-ray and ultraviolet spectra of the system 4U 0900-40/HD 77581 and explain the suppression of the absorption profiles of the Si IV upsilon 1394 and C IV upsilon 1548 lines when the X-ray sources is in front of the star. The model predicts that the absorption profiles of the N V upsilon 1239 and O VI upsilon 1032 lines will be enhanced rather than suppressed during this orbital phase. We predict phase-dependent linear polarization in the resonance lines profiles. Future observations of these phase dependent effects in early-type binary X-ray systems may be used to investigate the dynamics of stellar winds and their interactions with the X-ray source.
Test of Weak Equivalence Principle with the Multi-band Timing of the Crab Pulsar

The Weak Equivalent Principle (WEP) can be tested through the parameterized post-Newtonian parameter γ, representing the space curvature produced by unit rest mass. The parameter γ in turn has been constrained by comparing the arrival times of photons originating in distant transient events, such as gamma-ray bursts, fast radio bursts, and giant pulses of pulsars. Those measurements normally correspond to an individual burst event with very limited energy bands and signal-to-noise ratios (S/Ns). In this paper, the discrepancy in the pulse arrival times of the Crab Pulsar between different energy bands is obtained by the phase difference between corresponding pulse profiles. This allows us to compare the pulse arrival times at the largest energy band differences, between radio and optical, radio and X-ray, and radio and gamma-ray respectively. Because the pulse profiles are generated by phase-folding thousands of individual pulses, the time discrepancies between two energy bands are actually measured from thousands of events at each energy band, which corresponds to a much higher S/N. The upper limit of the γ discrepancy set by such an extensively observed and well-modeled source is as follows: at the energy difference of , at the energy difference of , at , and at . This actually measures the arrival times of freely falling photons in the gravitational field of the Milky Way with the largest amount of events and with data of the highest S/N, which tests WEP at energy band differences that have never been reached before.
The Optical Gravitational Lensing Experiment: Short Distance Scaleto the Large Magellanic Cloud

We present UBVI photometry of the eclipsing binary HV 2274—the system that has been recently used for distance determination to the LMC by Guinan et al. We determine the interstellar reddening to the star, E(B-V)=0.149±0.015 mag, based on observed color indices of the star. This value is in excellent agreement with the mean reddening toward HV 2274 obtained from photometry of the red clump stars in the surrounding field. The reddening is almost twice as large as determined by Guinan et al. We discuss the consequences of reddening underestimation. Most likely, HV 2274 is located much closer with the distance modulus to the star and the LMC (m-M=18.22±0.13 mag) supporting the short distance scale to the LMC. Such a distance modulus is in excellent agreement with the recent distance determinations with RR Lyrae and red clump stars.
ONE-DIMENSIONAL KONDO LATTICE MODEL AS A TOMONAGA-LUTTINGER LIQUID

Arguments are presented that in the one-dimensional Kondo lattice model $f$-electron spins participate in filling of the Fermi sea. It is shown that in its paramagnetic phase this model belongs to the spin-1/2 Tomonaga-Luttinger liquid universality class. The ratio of the spin and charge velocities ${v}_{\ensuremath{\sigma}}{/v}_{\ensuremath{\rho}}$ and ${K}_{\ensuremath{\rho}}$ are estimated to be of the order of ${(T}_{K}/{\ensuremath{\epsilon}}_{F}{)}^{1/2}$.