Miracle-dz/UniFAR-FTUs huggingface dataset:
Topological quantum phase transitions of attractive spinless fermions in a honeycomb lattice

We investigate a spinless Fermi gas trapped in a honeycomb optical lattice with attractive nearest-neighbor interactions. At zero temperature, the mean-field theory predicts three quantum phase transitions, two being topological. At low interactions, the system is semi-metallic. Increasing the interaction further, the semi-metal destabilizes into a fully gapped superfluid. At larger interactions, a topological transition occurs and this superfluid phase becomes gapless, with Dirac-like dispersion relations. Finally, increasing again the interaction, a second topological transition occurs and the gapless superfluid is replaced by a different fully gapped superfluid phase. We analyze these different quantum phases as the temperature and the lattice filling are varied.
(2$+$1)-dimensional gravity from Maxwell and semisimple extension of the Poincaré gauge symmetric models

We obtain 2 + 1 dimensional gravity with cosmological constant which is coupled to gauge fields, using Maxwell and semi-simple extension of the Poincare gauge symmetric models (i.e. Chern-Simons models with these gauge groups). Also, we obtain some Ads and BTZ type solutions for the classical equations of motion for these 2 + 1 dimensional gravities. For the semi-simple extension of the Poincare gauge group we investigate the Ads/CFT correspondence and show that the model at the boundary is equivalent to the sum of three WZW models over group SO(2,1). Then, we show that the central charge of the CFT is the same as that of CFT at the boundary of Ads spacetime related to the Chern-Simons model with gauge group SO(2,2). Finally, we show that these two 2 + 1 dimensional gravity models are dual (canonically transformed) to each other.
ALMA Reveals an Inhomogeneous Compact Rotating Dense Molecular Torus at the NGC 1068 Nucleus

We present the results of our ALMA Cycle 4 high-spatial-resolution (0.04-0.07") observations, at HCN J=3-2 and HCO+ J=3-2 lines, of the nucleus of NGC 1068, the nearby prototypical type 2 active galactic nucleus (AGN). Our previous ALMA observations identified the compact emission of these lines at the putative location of the torus around a mass-accreting supermassive black hole. We now report that we have detected the rotation of this compact emission, with the eastern and western sides being redshifted and blueshifted, respectively. Unlike the previously reported CO J=6-5 emission, both the morphological and dynamical alignments of the HCN J=3-2 and HCO+ J=3-2 emission are roughly aligned along the east-west direction (i.e., the expected torus direction), suggesting that these molecular lines are better probes of a rotating dense molecular gas component in the torus. The western part of the torus exhibits larger velocity dispersion and stronger emission in the HCN J=3-2 and HCO+ J=3-2 lines than the eastern part, revealing a highly inhomogeneous molecular torus. The dense molecular gas in the torus and that of the host galaxy at 0.5-2.0" from the AGN along the torus direction are found to be counter-rotating, suggesting an external process happened in the past at the NGC 1068 nucleus.
ALMA OBSERVATIONS OF THE IRDC CLUMP G34.43+00.24 MM3: DNC/HNC RATIO

We have observed the clump G34.43+00.24 MM3 associated with an infrared dark cloud in DNC J = 3–2, HN13C J = 3–2, and N2H+ J = 3–2 with the Atacama Large Millimeter/submillimeter Array (ALMA). The N2H+ emission is found to be relatively weak near the hot core and the outflows, and its distribution is clearly anti-correlated with the CS emission. This result indicates that a young outflow is interacting with cold ambient gas. The HN13C emission is compact and mostly emanates from the hot core, whereas the DNC emission is extended around the hot core. Thus, the DNC and HN13C emission traces warm regions near the protostar differently. The DNC emission is stronger than the HN13C emission toward most parts of this clump. The DNC/HNC abundance ratio averaged within a 15 ″ ? > × 15 ″ ? > area around the phase center is higher than 0.06. This ratio is much higher than the value obtained by the previous single-dish observations of DNC and HN13C J = 1–0 (∼0.003). It seems likely that the DNC and HNC emission observed with the single-dish telescope traces lower density envelopes, while that observed with ALMA traces higher density and highly deuterated regions. We have compared the observational results with chemical-model results in order to investigate the behavior of DNC and HNC in the dense cores. Taking these results into account, we suggest that the low DNC/HNC ratio in the high-mass sources obtained by the single-dish observations are at least partly due to the low filling factor of the high density regions.
On Blaschke’s conjecture

The Blaschke's conjecture asserts that if $\diam(M)=\text{Inj}(M)=\frac\pi2$ (up to a rescaling) for a complete Riemannian manifold $M$, then $M$ is isometric to $\Bbb S^n(\frac12)$, ${\Bbb R\Bbb P}^{n}$, ${\Bbb C\Bbb P}^{n}$, ${\Bbb H\Bbb P}^{n}$ or ${\Bbb Ca\Bbb P}^{2}$ endowed with the canonical metric. In the paper, we prove that the conjecture is true if we in addition assume that $\sec_M\geq1$.
Closing the proximity gap in a metallic Josephson junction between three superconductors

We describe the proximity effect in a short disordered metallic junction between three superconducting leads. Andreev bound states in the multiterminal junction may cross the Fermi level. We reveal that for a quasicontinuous metallic density of states, crossings at the Fermi level manifest as a closing of the proximity-induced gap. We calculate the local density of states for a wide range of transport parameters using quantum circuit theory. The gap closes inside an area of the space spanned by the superconducting phase differences. We derive an approximate analytic expression for the boundary of the area and compare it to the full numerical solution. The size of the area increases with the transparency of the junction and is sensitive to asymmetry. The finite density of states at zero energy is unaffected by the electron-hole decoherence present in the junction, although decoherence is important at higher energies. Our predictions can be tested using tunneling transport spectroscopy. To encourage experiments, we calculate the current-voltage characteristic in a typical measurement setup. We show how the structure of the local density of states can be mapped out from the measurement.
Submillimeter/millimeter observations of the molecular clouds associated with Tycho＇s supernova remnant

We have carried out CO J = 2 - 1 and CO J = 3 - 2 observations toward Tycho's supernova remnant (SNR) using the KOSMA 3m-telescope. From these observations, we identified three molecular clouds (MCs) around the SNR. The small cloud in the southwest was discovered for the first time. In the north and east, two MCs (Cloud A and Cloud B) adjacent in space display a bow-shaped morphology, and have broad emission lines, which provide some direct evidences of the SNR-MCs interaction. The MCs are revealed at -69~ -59 km s -1 , coincident with Tycho's SNR. The MCs associated with Tycho's SNR have a mass of ~ 2.13 × 10 3 M ⊙ . Position-velocity diagrams show the two clouds to be adjacent in velocity, which means cloud-cloud collision could occur in this region. The maximum value (0.66 ± 0.10) of the integrated CO line intensity ratio (I CO J =3-2 /I CO J =2-1 ) for the three MCs agrees well with the previous measurement of individual Galactic MCs, implying that the SNR shock drove into the MCs. The two MCs have a line intensity ratio gradient. The distribution of the ratio appears to indicate that the shock propagates from the southwest to the northeast.
On the entanglement across a cubic interface in 3+1 dimensions

We calculate the area, edge and corner Renyi entanglement entropies in the ground state of the transverse-field Ising model, on a simple-cubic lattice, by high-field and low-field series expansions. We find that while the area term is positive and the line term is negative as required by strong subadditivity, the corner contributions are positive in 3-dimensions. Analysis of the series suggests that the expansions converge up to the physical critical point from both sides. The leading area-law Renyi entropies match nicely from the high and low field expansions at the critical point, forming a sharp cusp there. We calculate the coefficients of the logarithmic divergence associated with the corner entropy and compare them with conformal field theory results with smooth interfaces and find a striking correspondence.
Police executive leadership: An empirical and theoretical exploration of police chief performance

To date, most studies of police leadership have focused on lower and mid-level police managers, with few scholars having studied the leadership performance of police chiefs. This study contributes to the literature with an empirical assessment and theoretical consideration of leadership at the top executive level of police departments. Police chiefs who attended professional training programs at the Bill Blackwood Law Enforcement Management Institute of Texas evaluated the prior police chief's performance of multiple duties such as directing the work of employees, initiating changes in the department and working with other agencies. Factor analyses of the data indicate the measures load onto three clusters, the composition of which are incompatible with any single theory of leadership. These findings indicate the executive leadership of a police department may be distinct from the leadership of other types of organizations. Incorporating insights from skill-based and situational leadership theories, it is suggested that police executive leadership may be conceptualized as an amalgam of conceptual, managerial and political skills that are shaped by and tailored to the audience and situation.
ODYSSEY: A PUBLIC GPU-BASED CODE FOR GENERAL RELATIVISTIC RADIATIVE TRANSFER IN KERR SPACETIME

General relativistic radiative transfer calculations coupled with the calculation of geodesics in the Kerr spacetime are an essential tool for determining the images, spectra, and light curves from matter in the vicinity of black holes. Such studies are especially important for ongoing and upcoming millimeter/submillimeter very long baseline interferometry observations of the supermassive black holes at the centers of Sgr A* and M87. To this end we introduce Odyssey, a graphics processing unit (GPU) based code for ray tracing and radiative transfer in the Kerr spacetime. On a single GPU, the performance of Odyssey can exceed 1 ns per photon, per Runge–Kutta integration step. Odyssey is publicly available, fast, accurate, and flexible enough to be modified to suit the specific needs of new users. Along with a Graphical User Interface powered by a video-accelerated display architecture, we also present an educational software tool, Odyssey_Edu, for showing in real time how null geodesics around a Kerr black hole vary as a function of black hole spin and angle of incidence onto the black hole.
POWERFUL ACTIVITY IN THE BRIGHT AGES. I. A VISIBLE/IR SURVEY OF HIGH REDSHIFT 3C RADIO GALAXIES AND QUASARS

We present new rest-frame UV and visible observations of 22 high-z (1 < z < 2.5) 3C radio galaxies and QSOs obtained with the Hubble Space Telescope’s Wide Field Camera 3 instrument. Using a custom data reduction strategy in order to assure the removal of cosmic rays, persistence signal, and other data artifacts, we have produced high-quality science-ready images of the targets and their local environments. We observe targets with regions of UV emission suggestive of active star formation. In addition, several targets exhibit highly distorted host galaxy morphologies in the rest frame visible images. Photometric analyses reveal that brighter QSOs generally tend to be redder than their dimmer counterparts. Using emission line fluxes from the literature, we estimate that emission line contamination is relatively small in the rest frame UV images for the QSOs. Using archival VLA data, we have also created radio map overlays for each of our targets, allowing for analysis of the optical and radio axes alignment.
Evaluation of the Piezoresistivity of a Thin Film of ZnO Doped with Fluorine and Deposited via the Ultrasonic Spray Pyrolysis Technique for Applications in Micro/Nano-Electromechanical Sensors

In this study, thin films of zinc oxide doped with fluorine ZnO: F were deposited via ultrasonic spray pyrolysis (USP) with an atomic ratio of [F/Zn] in a starting solution of 15 at. % on borosilicate glass coverslips and SiO2/Si substrates. The structure, electrical resistivity, and thickness were obtained via X-ray diffraction, the four-point technique, and profilometry, respectively. A ZnO: F piezoresistor was modeled at the fixed end of the cantilever through lithography and chemical etching. A SiO2/Si cantilever structure was used to evaluate the piezoresistivity of a ZnO: F thin film, and temperature coefficient of resistance (TCR) measurements were performed in an electric furnace. The strain on the ZnO: F piezoresistor caused by the application of masses at the free end of the cantilever was determined using a theoretical equation, in addition to a simulation in the COMSOL Multiphysics 5.3a FEM (finite element method) software considering the dimensions and materials of the manufactured device. The ZnO: F thin films were hexagonal wurtzite (phase 002), with thicknesses in the range from 234 nm to 295 nm and with resistivities of the order of 10−2 Ω. cm. The ZnO: F thin-film piezoresistor showed a gauge factor (GF) of 12.7 and a TCR of −3.78 × 10−3 %/K up to 525 K, which are suitable properties for sensor development.
APSARA: A multi-dimensional unsplit fourth-order explicit Eulerian hydrodynamics code for arbitrary curvilinear grids

We present a new fourth-order, finite-volume hydrodynamics code named Apsara. The code employs a high-order, finite-volume method for mapped coordinates with extensions for nonlinear hyperbolic conservation laws. Apsara can handle arbitrary structured curvilinear meshes in three spatial dimensions. The code has successfully passed several hydrodynamic test problems, including the advection of a Gaussian density profile and a nonlinear vortex and the propagation of linear acoustic waves. For these test problems, Apsara produces fourth-order accurate results in case of smooth grid mappings. The order of accuracy is reduced to first-order when using the nonsmooth circular grid mapping. When applying the high-order method to simulations of low-Mach number flows, for example, the Gresho vortex and the Taylor-Green vortex, we discover that Apsara delivers superior results to codes based on the dimensionally split, piecewise parabolic method (PPM) widely used in astrophysics. Hence, Apsara is a suitable tool for simulating highly subsonic flows in astrophysics. In the first astrophysical application, we perform implicit large eddy simulations (ILES) of anisotropic turbulence in the context of core collapse supernova (CCSN) and obtain results similar to those previously reported.
Chiral Symmetry transition in the Linear Sigma Model with quarks: Counting effective QCD degrees of freedom from low to high temperature

We use the linear sigma model coupled to quarks, together with a plausible location of the critical end point (CEP), to study the chiral symmetry transition in the QCD phase diagram. We compute the effective potential at finite temperature and density up to the contribution of the ring diagrams, both in the low and high temperature limits, and use it to compute the pressure and the position of the CEP. In the high temperature regime, by comparing to results from extrapolated lattice data, we determine the model coupling constants. Demanding that the CEP remains in the same location when described in the high temperature limit, we determine again the couplings and the pressure for the low temperature regime. We show that this procedure gives an average description of the lattice QCD results for the pressure and that the change from the low to the high temperature domains in this quantity can be attributed to the change in the coupling constants which in turn we link to the change in the effective degrees of freedom.
Sedimentation of Inertialess Particles in Stokes Flows

Abstract We investigate the sedimentation of a cloud of rigid, spherical particles of identical radii under gravity in a Stokes fluid. Both inertia and rotation of particles are neglected. We consider the homogenization limit of many small particles in the case of a dilute system in which interactions between particles are still important. In the relevant time scale, we rigorously prove convergence of the dynamics to the solution of a macroscopic equation. This macroscopic equation resembles the Stokes equations for a fluid of variable density subject to gravitation.
Ionization signals from electrons and alpha-particles in mixtures of liquid Argon and Nitrogen – perspectives on protons for Gamma Resonant Nuclear Absorption applications

In this paper we report on a detailed study of ionization signals produced by Compton electrons and alpha-particles in a Time Projection Chamber (TPC) filled with different mixtures of liquid Argon and Nitrogen. The measurements were carried out with Nitrogen concentrations up to 15% and a drift electric field in the range 0-50 kV/cm. A prediction for proton ionization signals is made by means of interpolation. This study has been conducted in view of the possible use of liquid Ar−N2 TPCs for the detection of gamma-rays in the resonant band of the Nitrogen absorption spectrum, a promising technology for security and medical applications.
Vertex operator representations of quantum affine superalgebras

Let Uq(g) be the quantum affine superalgebra associated with an affine Kac-Moody superalgebra g which belongs to the three series osp(1|2n)^(1),sl(1|2n)^(2) and osp(2|2n)^(2). We develop vertex operator constructions for the level 1 irreducible integrable highest weight representations and classify the finite dimensional irreducible representations of Uq(g). This makes essential use of the Drinfeld realisation for Uq(g), and quantum correspondences between affine Kac-Moody superalgebras, developed in earlier papers.
The Clifford Algebra approach to Quantum Mechanics A: The Schroedinger and Pauli Particles

In this paper we show how all the quantum properties of Schroedinger and Pauli particles can be described entirely from within a Clifford algebra taken over the reals. There is no need to appeal to any `wave function'. To describe a quantum system, we define the Clifford density element [CDE] as a product of an element of a minimal left ideal and its Clifford conjugate. The properties of the system are then completely specified in terms of bilinear invariants of the first and second kind calculated using the CDE. Thus the quantum properties of a system can be completely described from within the algebra without the need to appeal to any Hilbert space representation. Furthermore we show that the essential bilinear invariants of the second kind are simply the Bohm energy and the Bohm momentum, entities that make their appearance in the Bohm interpretation. We also show how these parameters emerge from standard quantum field theory in the low energy, single particle approximation. There is no need to appeal to classical mechanics at any stage. This clearly shows that the Bohm approach is entirely within the standard quantum formalism. The method has enabled us to lay the foundations of an approach that can be extended to provide a complete relativistic version of Bohm model. In this paper we confine our attention to the details of the non-relativistic case and will present its relativistic extension in a subsequent paper.
Curvature perturbations and non-Gaussianities from the waterfall phase transition during inflation

We consider a variant of hybrid inflation where the waterfall phase transition occurs during inflation. By adjusting the parameters associated with the mass of the waterfall field, we can achieve a phase transition that is not sharp, thus inflation can proceed for about 50–60 e-folds after the waterfall phase transition. We show that one can work within the limit where the quantum back-reactions are subdominant compared to the classical back-reactions. It is shown that a significant amount of large scale curvature perturbations are induced from the entropy perturbations. The curvature perturbation spectral index is either blue or red depending on whether the mode of interest leaves the horizon before the phase transition or after the phase transition. This can have interesting observational consequences on CMB. The non-Gaussianity parameter fNL is calculated to be ≲ 1 but much bigger than the slow-roll parameters.
A VOLUME-LIMITED SAMPLE OF 63 M7–M9.5 DWARFS. II. ACTIVITY, MAGNETISM, AND THE FADE OF THE ROTATION-DOMINATED DYNAMO

In a volume-limited sample of 63 ultracool dwarfs of spectral type M7–M9.5, we have obtained high-resolution spectroscopy with UVES at the Very Large Telescope and HIRES at Keck Observatory. In this second paper, we present projected rotation velocities, average magnetic field strengths, and chromospheric emission from the Hα line. We confirm earlier results that the mean level of normalized Hα luminosity decreases with lower temperature, and we find that the scatter among Hα luminosities is larger at lower temperature. We measure average magnetic fields between 0 and 4 kG with no indication for a dependence on temperature between M7 and M9.5. For a given temperature, Hα luminosity is related to magnetic field strength, consistent with results in earlier stars. A few very slowly rotating stars show very weak magnetic fields and Hα emission, and all stars rotating faster than our detection limit show magnetic fields of at least a few hundred Gauss. In contrast to earlier-type stars, we observe magnetic fields weaker than 1 kG in stars rotating faster than ∼3 km s−1, but we find no correlation between rotation and magnetic flux generation among them. We interpret this as a fundamental change in the dynamo mechanism; in ultracool dwarfs, magnetic field generation is predominantly achieved by a turbulent dynamo, while other mechanisms can operate more efficiently at earlier spectral types.
Korean Drama Scene Transcript Dataset for Emotion Recognition in Conversations

Understanding emotions in conversation is a challenging task, as the sentences often have an implied meaning that is not generally understood in isolation. Efficient use of contextual information is essential for emotion recognition in conversations. Many published datasets provide contextual information for situations such as text-based online messaging, chatbots, and movie dialogues. However, such dialogue-based datasets are collected by selecting ideal conversational situations and thus do not include many variations in dialogue length and number of participants. Therefore, such datasets may not be applicable for emotion recognition in text-based movie transcripts, where scenes contain variations in the number of speakers and length of spoken sentences. We present a conversation dataset based on the Korean television show transcripts to analyze the emotions in presence of scene context. The Korean Drama Scene Transcript dataset for Emotion Recognition (KD-EmoR) is a text-based conversation dataset. We analyze three classes of complex emotions: euphoria, dysphoria, and neutral, in the scenes of a television drama to build a publicly available dataset for further research. We developed a context-aware deep learning model to classify emotions using the speaker-level context and scene context and achieved an F1-score of 0.63 on the proposed dataset.