Miracle-dz/UniFAR-FTUs huggingface dataset:
Klein–Gordon Oscillator in a Topologically Nontrivial Space-Time

In this study, we analyze solutions of the wave equation for scalar particles in a space-time with nontrivial topology. Solutions for the Klein–Gordon oscillator are found considering two configurations of this space-time. In the first one, the S1×R3 space is assumed where the metric is written in the usual inertial frame of reference. In the second case, we consider a rotating reference frame adapted to the circle S1. We obtained compact expressions for the energy spectrum and for the particles wave functions in both configurations. Additionally, we show that the energy spectrum of the solution associated with the rotating system has an additional term that breaks the symmetry around E=0.
WIMP Dark Matter and the QCD Equation of State

Weakly Interacting Massive Particles (WIMPs) of mass m freeze out at a temperature T f ≃ m/ 25, i.e. in the range 400 MeV – 40 GeV for a particle in the typical mass range 10 – 1000 GeV. The WIMP relic density, which depends on the eﬀective number of relativistic degrees of freedom at T f , may be measured to better than 1% by Planck, warranting comparable theoretical precision. Recent theoretical and experimental advances in the understanding of high temperature QCD show that the quark gluon plasma departs signiﬁcantly from ideal behaviour up to temperatures of several GeV, necessitating an improvement of the cosmological equation of state over those currently used. We discuss how this increases the relic density by approximately 1.5 – 3.5% in benchmark mSUGRA models, with an uncertainly in the QCD corrections of 0.5 – 1 %. We point out what further work is required to achieve a theoretical accuracy comparable with the expected observational precision, and speculate that the eﬀective number of degrees of freedom at T f may become measurable in the foreseeable future.
Light propagation through black-hole lattices

The apparent properties of distant objects encode information about the way the light they emit propagates to an observer, and therefore about the curvature of the underlying spacetime. Measuring the relationship between the redshift z and the luminosity distance DL of a standard candle, for example, yields information on the Universe's matter content. In practice, however, in order to decode this information the observer needs to make an assumption about the functional form of the DL(z) relation; in other words, a cosmological model needs to be assumed. In this work, we use numerical-relativity simulations, equipped with a new ray-tracing module, to numerically obtain this relation for a few black-hole-lattice cosmologies and compare it to the well-known Friedmann-Lema{ȋtre-Robertson-Walker case, as well as to other relevant cosmologies and to the Empty-Beam Approximation. We find that the latter provides the best estimate of the luminosity distance and formulate a simple argument to account for this agreement. We also find that a Friedmann-Lema{ȋtre-Robertson-Walker model can reproduce this observable exactly, as long as a time-dependent cosmological constant is included in the fit. Finally, the dependence of these results on the lattice mass-to-spacing ratio μ is discussed: we discover that, unlike the expansion rate, the DL(z) relation in a black-hole lattice does not tend to that measured in the corresponding continuum spacetime as 0μ → .
Chandra Observations of Radio-Loud Quasars at z > 4: X-Rays from the Radio Beacons of the Early Universe

We present the results of Chandra observations of six radio-loud quasars (RLQs) and one optically bright radio-quiet quasar (RQQ) at z ≈ 4.1–4.4. These observations cover a representative sample of RLQs with moderate radio loudness (R ≈ 40–400), filling the X-ray observational gap between optically selected RQQs (predominantly R ≲ 2–10) and the five known blazars at z > 4 (R ≈ 800–27,000), where R = f5GHz/f4400Å (rest frame). We study the relationship between X-ray luminosity and radio loudness for quasars at high redshift and constrain RLQ X-ray continuum emission and absorption. From a joint spectral fit of nine moderate-R RLQs observed by Chandra, we find tentative evidence for absorption above the Galactic NH, with a best-fit neutral intrinsic column density of NH = 2.4 × 1022 cm-2, consistent with earlier claims of increased absorption toward high-redshift RLQs. We also search for evidence of an enhanced jet-linked component in the X-ray emission due to the increased energy density of the cosmic microwave background at high redshift, but we find neither spatial detections of X-ray jets nor a significant enhancement in the X-ray emission relative to comparable RLQs at low to moderate redshifts. Overall, the z ≈ 4–5 RLQs have basic X-ray properties consistent with comparable RLQs in the local universe, suggesting that the accretion/jet mechanisms of these objects are similar as well.
Bulk transport properties of Bismuth selenide thin films approaching the two-dimensional limit

We have investigated the transport properties of topological insulator Bi2Se3 thin films grown using magnetron sputtering with an emphasis on understanding the behavior as a function of thickness. We show that thickness has a strong influence on all aspects of transport as the two-dimensional limit is approached. Bulk resistivity and Hall mobility show disproportionately large changes below 6 quintuple layer which we directly correlate to an increase in the bulk band gap of few-layer Bi2Se3, an effect that is concomitant with surface gap opening. A tendency to crossover from a metallic to an insulating behavior in temperature-dependent resistivity measurements in ultra-thin Bi2Se3 is also consistent with an increase in the bulk band gap along with enhanced disorder at the film-substrate interface. Our work highlights that the properties of few-layer Bi2Se3 are tunable that may be attractive for a variety of device applications in areas such as optoelectronics, nanoelectronics and spintronics.
The baryonic Tully–Fisher relation for different velocity definitions and implications for galaxy angular momentum

We study the baryonic Tully–Fisher relation (BTFR) at z ≃ 0 using 153 galaxies from the Spitzer Photometry and Accurate Rotation Curve sample. We consider different definitions of the characteristic velocity from H I and H α rotation curves, as well as H I line-widths from single-dish observations. We reach the following results: (1) The tightest BTFR is given by the mean velocity along the flat part of the rotation curve. The orthogonal intrinsic scatter is extremely small (⁠∼6 per cent⁠) and the best-fitting slope is 3.85 ± 0.09, but systematic uncertainties may drive the slope from 3.5 to 4.0. Other velocity definitions lead to BTFRs with systematically higher scatters and shallower slopes. (2) We provide statistical relations to infer the flat rotation velocity from H I line-widths or less extended rotation curves (like H α and CO data). These can be useful to study the BTFR from large H I surveys or the BTFR at high redshifts. (3) The BTFR is more fundamental than the relation between angular momentum and galaxy mass (the Fall relation). The Fall relation has about seven times more scatter than the BTFR, which is merely driven by the scatter in the mass-size relation of galaxies. The BTFR is already the ‘Fundamental Plane’ of galaxy discs: no value is added with a radial variable as a third parameter.
Flow properties of particles in a model annular shear cell

In order to quantitatively investigate the mechanical and rheological properties of solid flow in a shear cell under conditions relevant to those in an annular cell, we performed a series of discrete particle simulations of slightly polydispersed spheres from quasi-static to intermediate flow regimes. It is shown that the average values of stress tensor components are uniformly distributed in the cell space away from the stationary walls; however, some degree of inhomogeneity in their spatial distributions does exist. A linear relationship between the (internal/external) shear and normal stresses prevails in the shear cell and the internal and external friction coefficients can compare well with each other. It is confirmed that annular shear cells are reasonably effective as a method of measuring particle flow properties. The so-called I-rheology proposed by Jop et al. [Nature (London) 441, 727 (2006)] is rigorously tested in this cell system. The results unambiguously display that the I-rheology can effe.
Orbital Motion of the Wide Planetary-mass Companion GSC 6214-210 b: No Evidence for Dynamical Scattering

Direct-imaging exoplanet surveys have discovered a class of 5–20 substellar companions at separations >100 au from their host stars, which present a challenge to planet and star formation models. Detailed analysis of the orbital architecture of these systems can provide constraints on possible formation mechanisms, including the possibility that they were dynamically ejected onto a wide orbit. We present astrometry for the wide planetary-mass companion GSC 6214-210 b (240 au; ≈14 ) obtained using NIRC2 with adaptive optics at the Keck telescope over 10 years. Our measurements achieved astrometric uncertainties of ≈1 mas per epoch. We determined a relative motion of 1.12 ± 0.15 mas yr−1 (0.61 ± 0.09 km s−1), the first detection of orbital motion for this companion. We compute the minimum periastron for the companion due to our measured velocity vector and derive constraints on the orbital parameters through our modified implementation of the Orbits for the Impatient rejection sampling algorithm. We find that close periastron orbits, which could indicate that the companion was dynamically scattered, are present in our posterior but have low likelihoods. For all orbits in our posterior, we assess the detectability of close-in companions that could have scattered GSC 6214-210 b from a closer orbit, and find that most potential scatterers would have been detected in previous imaging. We conclude that formation at small orbital separation and subsequent dynamical scattering through interaction with another potential close-in object is an unlikely formation pathway for this companion. We also update stellar and substellar properties for the system using the new parallax from Gaia DR2.
Large Magellanic Cloud Near-infrared Synoptic Survey. IV. Leavitt Laws for Type II Cepheid Variables

We present time-series observations of Population II Cepheids in the Large Magellanic Cloud at near-infrared (JHKs) wavelengths. Our sample consists of 81 variables with accurate periods and optical (VI) magnitudes from the OGLE survey, covering various subtypes of pulsators (BL Herculis, W Virginis, and RV Tauri). We generate light-curve templates using high-quality I-band data in the LMC from OGLE and Ks-band data in the Galactic bulge from VISTA Variables in Via LÃ¡ctea survey and use them to obtain robust mean magnitudes. We derive period–luminosity (P–L) relations in the near-infrared and Period–Wesenheit (P–W) relations by combining optical and near-infrared data. Our P–L and P–W relations are consistent with published work when excluding long-period RV Tauris. We find that Pop II Cepheids and RR Lyraes follow the same P–L relations in the LMC. Therefore, we use trigonometric parallax from the Gaia DR1 for VY Pyx and the Hubble Space Telescope parallaxes for k Pav and 5 RR Lyrae variables to obtain an absolute calibration of the Galactic Ks-band P–L relation, resulting in a distance modulus to the LMC of mag. We update the mean magnitudes of Pop II Cepheids in Galactic globular clusters using our light-curve templates and obtain distance estimates to those systems, anchored to a precise late-type eclipsing binary distance to the LMC. We find that the distances to these globular clusters based on Pop II Cepheids are consistent (within ) with estimates based on the relation for horizontal branch stars.
Crime and firm performance: Empirical evidence from the Balkan region

This paper aims to analyze the impact of business-related crime on the performance of Kosovo firms. This also represents the research problem of this paper. The sample of firms consists of 200 firms from different economic sectors. This research is based on the research of Moyo (2012) and Botrić (2021) who used similar variables related to this issue. Through the ordinary least squares (OLS) econometric model, the results have been obtained that show that criminality or different types of crime of a business nature have a negative impact on the performance of these firms. Also, the results obtained prove that firms from the region of Pristina and Mitrovica are more exposed to crime, while as for the size of the firms, medium-sized firms are more exposed to crime compared to other firms. Firms in the textile and wood sectors, compared to firms in other sectors, are most affected by crime. Business associations and government institutions should design state policies that would ensure a safe environment for all firms in all regions of Kosovo and economic sectors. The relevance of this research lies in the fact that these findings have never been elaborated on by other authors from Kosovo.
Site-specific Knight shift measurements of the dilute Kondo lattice system 
Ce1−xLaxCoIn5

$^{115}\mathrm{In}$ nuclear magnetic resonance data are presented for a series of ${\mathrm{Ce}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}{\mathrm{CoIn}}_{5}$ crystals with different La dilutions $x$. Multiple In(1) sites associated with different numbers of nearest-neighbor cerium atoms exhibit different Knight shifts and spin lattice relaxation rates. Analysis of the temperature dependence of these sites reveals both an evolution of the heavy electron coherence as a function of dilution, as well as spatial inhomogeneity associated with a complete suppression of antiferromagnetic fluctuations in the vicinity of the La sites. Quantum critical fluctuations persist within disconnected Ce clusters with dilution levels up to 75%, despite the fact that specific heat shows Fermi liquid behavior in dilute samples.
Pro-Inflammatory Oral Microbiota in Juvenile Spondyloarthritis: A Pilot Study

The role of the microbiota in the pathogenesis of arthritis is gaining increasing attention. While multiple studies have queried the intestinal microbiota, very few have analyzed the contents of the oral microbiota. In this pilot study, we obtained salivary and sub-gingival specimens from a cohort of six healthy controls and five children with well-controlled spondyloarthritis (SpA) and performed 16S sequencing on bacteria obtained from both habitats. The Quantitative Insight into Microbial Ecology tool suite was used to generate operational taxonomic units, Phyloseq was used for diversity analyses, and DeSeq2 was used to compare abundances while adjusting for multiple comparisons. A repeat specimen was obtained from one subject during a flare. Clustering based upon diagnosis was observed from both habitats, with decreased alpha diversity seen within the plaque obtained from the patients vs. controls. Among the differentially abundant taxa were statistically significantly increased plaque Fusobacterium and salivary Rothia mucilaginosa among the patients compared to the controls. Additionally, the abundance of plaque Fusobacterium increased in one patient at the time of a flare. Our data suggest that the oral cavity may harbor bacteria involved in the pathogenesis of spondyloarthritis; additional studies are warranted.
Temperature-dependent spectral function of a Kondo impurity in an 
s
-wave superconductor

Using the numerical renormalization group method, the effect due to a Kondo impurity in an $s$-wave superconductor is examined at finite temperature ($T$). The $T$-behaviors of the spectral function and the magnetic moment at the impurity site are calculated. At $T$=0, the spin due to the impurity is in singlet state when the ratio between the Kondo temperature $T_k$ and the superconducting gap $\Delta$ is larger than 0.26. Otherwise, the spin of the impurity is in a doublet state. We show that the separation of the double Yu-Shiba-Rusinov peaks in the spectral function shrinks as $T$ increases if $T_k/\Delta 0.26$ and $\Delta$ remains to be a constant. These features could be measured by experiments and thus provide a unique way to determine whether the spin of the single Kondo impurity is in singlet or doublet state at zero temperature.
Thin edge-on galaxies as a tool for the investigation of large-scale streaming motions in the universe

A sample of 324 galaxies observed at Arecibo is used to demonstrate that thin edge-on galaxies can be used to study large-scale streaming motions in the universe. It is found that the scatter of galaxies in the Tully-Fisher (TF) diagram steadily decreases when the axial ratio a/b increases, and that for the flattest and most inclined galaxies (a/b of greater than 7), the scatter in the TF diagram yields a rms error in distance estimates of 10 exp + or - 0.09. A proposed catalogue of flat galaxies is described. 53 refs.
Nature of Faint Radio Sources in GOODS-North and GOODS-South Fields. I. Spectral Index and Radio–FIR Correlation

We present the first results from the deep and wide 5 GHz radio observations of the Great Observatories Origins Deep Survey (GOODS)-North (σ = 3.5 μJy beam−1, synthesized beam size θ = 1.″47 × 1.″42, and 52 sources over 109 arcmin2) and GOODS-South (σ = 3.0 μJy beam−1, θ = 0.″98 × 0.″45, and 88 sources over 190 arcmin2) fields using the Karl G. Jansky Very Large Array. We derive radio spectral indices α between 1.4 and 5 GHz using the beam-matched images and show that the overall spectral index distribution is broad even when the measured noise and flux bias are considered. We also find a clustering of faint radio sources around α = 0.8, but only within S5 GHz < 150 μJy. We demonstrate that the correct radio spectral index is important for deriving accurate rest-frame radio power and analyzing the radio–FIR correlation, and adopting a single value of α = 0.8 leads to a significant scatter and a strong bias in the analysis of the radio–FIR correlation, resulting from the broad and asymmetric spectral index distribution. When characterized by specific star formation rates, the starburst population (58%) dominates the 5 GHz radio source population, and the quiescent galaxy population (30%) follows a distinct trend in spectral index distribution and the radio–FIR correlation. Lastly, we offer suggestions on sensitivity and angular resolution for future ultra-deep surveys designed to trace the cosmic history of star formation and AGN activity using radio continuum as a probe.
Minimal barriers for geometric evolutions

We study some properties of De Giorgi's minimal barriers and local minimal barriers for geometric flows of subsets ofRn. Concerning evolutions of the form ∂u/∂t+F(∇u, ∇2u)=0, we prove a representation result for the minimal barrier M(E, FF) whenFis not degenerate elliptic; namely, we show that M(E, FF)= M(E, FF+), whereF+is the smallest degenerate elliptic function aboveF. We also characterize the disjoint sets property and the joint sets property in terms of the functionF.
Toppling the Ivory Tower: Increasing Public Participation in Research Through Open and Citizen Science

Prior to the emergence of professional researchers, amateurs without formal training primarily made contributions to science in what is known as ‘citizen science. ’ Over time, science has become less accessible to the public, while at the same time public participation in research has decreased. However, recent progress in open and citizen science may be the key to strengthening the relationship between researchers and the public. Citizen science may also be key to collecting data that would otherwise be unobtainable through traditional sources, such as measuring progress on the United Nations Sustainable Development Goals (SDGs). However, despite myriad benefits, there has been limited legislative action taken to promote open and citizen science policies. The underlying issues are incentive systems which overemphasize publication in high impact, for-profit journals. The suggested policy solutions include: 1) creating an open database for citizen science projects, 2) restricting publishers from disadvantaging citizen science, and 3) incorporating open science in researcher evaluation.
Various Wrapped Branes from Gauged Supergravities

We study wrapped brane configurations via possible maximally supersymmetric gauged supergravities. First, we construct various supersymmetric wrapped D3 brane configurations from D=5 N=8 SO(6) gauged supergravity. This procedure provides certain new examples of wrapped D3 branes around supersymmetric cycles inside non-compact special holonomy manifolds. We analyze their behaviors numerically in order to discuss a correspondence to Higgs and Coulomb branches of sigma models on wrapped D3 branes. We also realize supersymmetric wrapped M2 branes from D=4 N=8 SO(8) gauged supergravity. Then, we study supersymmetric wrapped type IIB NS5 branes by D=7 N=4 SO(4) gauged supergravity. We show a method to derive them by using supersymmetric wrapped M5 branes in D=7 N=4 SO(5) gauged supergravity. This method is based on a domain wall like reduction. Solutions include NS5 branes wrapped around holomorphic $CP^2$ inside non-compact Calabi-Yau threefold. Their behavior shows a similar feature to that for NS5 branes wrapped around holomorphic $CP^1$ inside non-compact $K3$ surface. This construction also provides a check of preserved supersymmetry for a solution interpreted within a string world-sheet theory introduced by Hori and Kapustin. Finally, we find new non-supersymmetric solutions including AdS space-times in D=6 N=2 $SU(2)\times U(1)$ massive gauged supergravity. These solutions can be interpreted as non-supersymmetric wrapped D4-D8 configurations which are dual to non-supersymmetric conformal field theories realized on wrapped D4 branes.
Anomalous thermal expansion and chiral phonons in 
BiB3O6

The origins of anomalous thermal expansion in the chiral monoclinic solid $\ensuremath{\alpha}\ensuremath{-}{\mathrm{BiB}}_{3}{\mathrm{O}}_{6}$ have been studied through ab initio calculations. Positive and negative axial thermal expansion are shown to be driven by librations of borate units, elastic anisotropy, and most notably by chiral acoustic phonons involving elliptical motions of bismuth atoms. The chirality of the lattice gives rise to these modes by allowing the transverse acoustic branches to have opposite circular polarizations, only one of which couples strongly to the lattice strains. These results further the understanding of relationships between crystallographic symmetry and physical properties.