Miracle-dz/UniFAR-FTUs huggingface dataset:
Quantum criticality in photorefractive optics: Vortices in laser beams and antiferromagnets

We study vortex patterns in a prototype nonlinear optical system: counterpropagating laser beams in a photorefractive crystal, with or without the background photonic lattice. The vortices are effectively planar and described by the winding number and the "flavor" index, stemming from the fact that we have two parallel beams propagating in opposite directions. The problem is amenable to the methods of statistical field theory and generalizes the Berezinsky-Kosterlitz-Thouless transition of the XY model to the "two-flavor" case. In addition to the familiar conductor and insulator phases, we also have the perfect conductor (vortex proliferation in both beams/"flavors") and the frustrated insulator (energy costs of vortex proliferation and vortex annihilation balance each other). In the presence of disorder in the background lattice, a novel phase appears which shows long-range correlations and absence of long-range order, thus being analogous to spin glasses. An important benefit of this approach is that qualitative behavior of patterns can be known without intensive numerical work over large areas of the parameter space. More generally, we would like to draw attention to connections between the (classical) pattern-forming systems in photorefractive optics and the methods of (quantum) condensed matter and field theory: on one hand, we use the field-theoretical methods (renormalization group, replica formalism) to analyze the patterns; on the other hand, the observed phases are analogous to those seen in magnetic systems, and make photorefractive optics a fruitful testing ground for condensed matter systems. As an example, we map our system to a doped $O(3)$ antiferromagnet with $\mathbb{Z}_2$ defects, which has the same structure of the phase diagram.
Note on Gauge Theories on M/Γ and the AdS/CFT Correspondence

It is well known that a weakly coupled U(N) gauge theory on a torus with sides of length L has extra light states with energies of order 1/(NL). We show that a similar result holds for gauge theories on M/Γ where M is any compact riemannian manifold and Γ is any freely acting discrete isometry group. As in the toroidal case, this is achieved by adding a suitable nontrivial flat connection. As one application, we consider the AdS/CFT correspondence on spacetimes asymptotic to AdS5/Γ. By considering finite size effects at nonzero temperature, we show that consistency requires these extra light states of the gauge theory on S3/Γ.
Truncated initial mass function in starburst galaxies

Observations of nearby star-forming regions suggest that the initial mass function is deficient in low-mass stars when the ambient star formation rate is high. We use new models of stellar population synthesis to investigate how a truncation of the lower end of the initial mass function affects the photometric evolution of starburst galaxies. A major difference with respect to the case of a standard initial mass function is that the spectra of the galaxies become unusually red (V-K≥3.5) when the turnoff mass reaches the lower mass cutoff. This red phase can last for more than 10 9 yr if the lower mass cutoff is below 2 M ○.
Optical conductivity of one-dimensional doped Hubbard-Mott insulator

We study the optical response of a strongly correlated electron system near the metal-insulator transition using a mapping to the sine-Gordon model. With semiclassical quantization, the spectral weight is distributed between a Drude peak and absorption lines due to breathers. We calculate the Drude weight, the optical gap, and the line shape of breather absorption.
Identification of extragalactic sources of the highest energy EGRET photons by correlation analysis

We have found significant correlations between the arrival directions of the highest energy photons (Eγ > 10 GeV) observed by EGRET and the positions of the BL Lac type objects (BL Lacs). The observed correlations imply that not less than 3 per cent of extragalactic photons at these energies originate from BL Lacs. Some of the BL Lacs that are correlated with the highest energy photons have no counterparts in the EGRET source catalogue, i.e. do not coincide with strong emitters of gamma-rays at lower energy. A study of correlating BL Lacs suggests that they may form a subset which is statistically different from the total BL Lac catalogue; we argue that they are prominent candidates for TeV gamma-ray sources. Our results demonstrate that the analysis of positional correlations is a powerful approach, indispensable in cases when low-number statistics limit or even prohibit the standard case-by-case identification. © 2006 RAS.
A deformation of AdS_5 x S^5

We analyse a one parameter family of supersymmetric solutions of type IIB supergravity that includes AdS_5 x S^5. For small values of the parameter the solutions are causally well-behaved, but beyond a critical value closed timelike curves (CTC's) appear. The solutions are holographically dual to N=4 supersymmetric Yang-Mills theory on a non-conformally flat background with non-vanishing R-currents. We compute the holographic energy-momentum tensor for the spacetime and show that it remains finite even when the CTC's appear. The solutions, as well as the uplift of some recently discovered AdS_5 black hole solutions, are shown to preserve precisely two supersymmetries.
Backward-emitted sub-Doppler fluorescence from an optically thick atomic vapor

Literature mentions only incidentally a sub-Doppler contribution in the excitation spectrum of the backward fluorescence of a dense vapor. This contribution is here investigated on Cs vapor, both on the first resonance line (894 nm) and on the weaker second resonance line (459 nm). We show that in a strongly absorbing medium, the quenching of excited atoms moving towards a window irradiated under near normal incidence reduces the fluorescence on the red side of the excitation spectrum. Atoms moving slowly towards the window produce a sub- Doppler velocity-selective contribution, whose visibility is here improved by applying a frequency-modulation technique. This sub-Doppler feature, induced by a surface quenching combined with a short absorption length for the incident irradiation, exhibits close analogies with the narrow spectra appearing with thin vapor cells. We also show that a normal incidence irradiation is essential for the sub-Doppler feature to be observed, while it should be independent of the detection geometry
Driving protocol for a Floquet topological phase without static counterpart

Periodically driven systems play a prominent role in optical lattices. In these ultracold atomic systems, driving is used to create a variety of interesting behaviours, of which an important example is provided by topological states of matter. Such Floquet topological phases have a richer classification than their equilibrium counterparts. Although there exist analogues of the equilibrium topological phases that are characterised by a Chern number, the corresponding Hall conductivity, and protected edge states, there is an additional possibility. This is a phase that has a vanishing Chern number and no Hall conductivity, but nevertheless hosts anomalous topological edge states (Rudner et al ( Phys. Rev. X 3 031005)). Due to experimental difficulties associated with the observation of such a phase, it has not been experimentally realised in optical lattices so far. In this paper, we show that optical lattices prove to be a good candidate for its realisation and observation, because they can be driven in a controlled manner. Specifically, we present a simple shaking protocol that serves to realise this special Floquet phase, discuss the specific properties that it has, and propose a method to experimentally detect this fascinating topological phase that has no counterpart in equilibrium systems.
Lepton number asymmetries and the lower bound on the reheating temperature

We show that the reheating temperature of a matter-domination era in the early universe can be pushed down to the neutrino decoupling temperature at around 2 MeV if the reheating takes place through non-hadronic decays of the dominant matter and neutrino-antineutrino asymmetries are still large enough, |L| ≳ 𝒪(10−2) (depending on the neutrino flavor) at the end of reheating.
A Model of Orbital Diffusion

Abstract It has been reported (Chapman et al. 1989, in Asteroids II, edited by R. P. Binzel, T. Gehrels, and M. S. Matthews, Univ. of Arizona Press, Tucson, p. 386) that the shapes of asteroid families tend to be asymmetric, with a relative flattening along the line toward the Sun. This article addresses that observation. We develop a simple model for this, with an initially localized cluster circularly orbiting the Sun in the ecliptic plane, and acted upon by a background of weak stochastic forces. The model's linearized equations of motion are such that a component of random force, perpendicular to the radius, acts back to affect the radial motion. The result is a flattening, over time, toward the Sun.
Diagenetic modification of kerogens

Kerogen is the part of sedimentary organic matter that is not petroleum. It can be isolated by using acid destruction of minerals, except in recent sediments where this procedure results in important hydrolysis reactions. Whether the scale of observation is microscopic or molecular, kerogens are heterogeneous mixtures whose compositions vary according to the sedimentation medium. However, they can be globally characterized by their H : C and O : C ratios. Diagenetic modification is a thermodynamically oriented process that consists of passing from complicated chemical structures inherited from living organisms or created during sedimentation to simple stable molecules. However, it is kinetically controlled by the thermal history of the sediment during burial. Three main steps are distinguished. (i) Diagenesis, where O :C decreases and CO2 and H2O are released. (ii) Catagenesis, where H : C decreases and petroleum and then gas are produced. (iii) Metagenesis, which consists of structural reorganization of the carbonaceous residue with little change in the elemental analysis. Modification can be followed by observing characteristic changes in physical and chemical properties.
Phase transitions in Abelian lattice gauge theories

We study the phase transition in the U (1) lattice gauge theory using the Wilson-Polyakov line as the order parameter. The Wilson-Polyakov line remains very small at strong coupling and becomes non-zero at weak coupling, signalling a confinement-to-deconfinement phase transition. The decondensation of monopole loops is responsible for this phase transition. A finite size scaling analysis of the susceptibility of the Wilson line gives a ratio for / which is quite close to the corresponding value in the three-dimensional planar model. A scaling behaviour of the monopole loop distribution function is also established at the point of the second-order phase transition. A measurement of the plaquette susceptibility at the transition point shows that it does not scale with the four-dimensional volume as is expected of a first-order bulk transition.
Species-Specific Patterns of Gut Metabolic Modules in Dutch Individuals with Different Dietary Habits

Diet is an important modulator of the human gut microbiome, which is susceptible to increased consumption of plant fibers in vegan or vegetarian lifestyles. To investigate this, we compared the gut microbiome of Dutch adults following omnivorous, pescatarian, vegan and vegetarian diets. ABSTRACT Diet is an important determinant of the human gut microbiome. Here, we analyzed fecal metagenomes of Dutch adults following omnivorous, pescatarian, vegan, and vegetarian diets. We compared the taxonomic composition of individuals from our study with publicly available gut metagenomes from westernized and non-westernized societies. We observed that, despite long-term transition to diets rich in plant fibers (vegan or vegetarian), the microbiomes of these were typical of westernized populations, and similar in composition to omnivores. Although there were no major differences in metabolic modules, we identified differences in the species that contributed to particular functions, such as carbohydrate degradation and short-chain fatty acid metabolism. Overall, this study shows functional redundancy of the microbiomes among westernized populations, which is independent of long-term individual dietary habits. IMPORTANCE Diet is an important modulator of the human gut microbiome, which is susceptible to increased consumption of plant fibers in vegan or vegetarian lifestyles. To investigate this, we compared the gut microbiome of Dutch adults following omnivorous, pescatarian, vegan and vegetarian diets. We did not observe major differences in the gut microbiome composition and function between individuals with different dietary habits. However, we observed differences in the species that contribute to the core functions of the gut microbiome. Our study thus emphasizes the need to better understand the species-specific functional changes associated with dietary habits in the human gut microbiome.
Dexmedetomidine in Psychiatry: Repurposing of its Fast-Acting Anxiolytic, Analgesic and Sleep Modulating Properties

Abstract Drug repurposing is a strategy to identify new indications for already approved drugs. A recent successful example in psychiatry is ketamine, an anesthetic drug developed in the 1960s, now approved and clinically used as a fast-acting antidepressant. Here, we describe the potential of dexmedetomidine as a psychopharmacological repurposing candidate. This α 2 -adrenoceptor agonist is approved in the US and Europe for procedural sedation in intensive care. It has shown fast-acting inhibitory effects on perioperative stress-related pathologies, including psychomotor agitation, hyperalgesia, and neuroinflammatory overdrive, proving potentially useful in clinical psychiatry. We offer an overview of the pharmacological profile and effects of dexmedetomidine with potential utility for the treatment of neuropsychiatric symptoms. Dexmedetomidine exerts fast-acting and robust sedation, anxiolytic, analgesic, sleep-modulating, and anti-inflammatory effects. Moreover, the drug prevents postoperative agitation and delirium, possibly via neuroprotective mechanisms. While evidence in animals and humans supports these properties, larger controlled trials in clinical samples are generally scarce, and systematic studies with psychiatric patients do not exist. In conclusion, dexmedetomidine is a promising candidate for an experimental treatment targeting stress-related pathologies common in neuropsychiatric disorders such as depression, anxiety disorders, and posttraumatic stress disorder. First small proof-of-concept studies and then larger controlled clinical trials are warranted in psychiatric populations to test the feasibility and efficacy of dexmedetomidine in these conditions.
Microstructure and superconducting properties of YBa2Cu3O7−δ thin films incorporated with a self-assembled magnetic vertically aligned nanocomposite

A thin layer of a vertically aligned nanocomposite (VAN) with separated phases of ferromagnetic Fe2O3 and non-magnetic CeO2, arranged as alternating nanopillars, is introduced in YBa2Cu3O7−δ (YBCO) thin films as either a cap or a buffer layer using a pulsed laser deposition method. Detailed microstructural characterization including XRD, high resolution XTEM and STEM is conducted and correlated with the superconducting properties to investigate the flux pinning properties introduced by the magnetic VAN layers. The Tc values of both doped samples are above 89 K and the measured at 65 K increased to 150% of that of the reference YBCO prepared under the same conditions. As the measurement temperature decreases, the magnetic pinning effect increases and the field dependent Jc(H ∥ c) is further improved to more than 200% of the Jc value of the reference YBCO sample. This suggests that the Fe2O3:CeO2 VAN can provide both ordered magnetic pillars and controlled defect density. Furthermore, the magnetic pillars are very effective pinning centers especially in the high field and low temperature regime.
Star Formation in Galaxies at z ∼ 4–5 from the SMUVS Survey: A Clear Starburst/Main-sequence Bimodality for Hα Emitters on the SFR–M* Plane

We study a large galaxy sample from the Spitzer Matching Survey of the UltraVISTA ultra-deep Stripes (SMUVS) to search for sources with enhanced 3.6 μ m fluxes indicative of strong Hα emission at z = 3.9 – 4.9 . We find that the percentage of “Hα excess” sources reaches 37%–40% for galaxies with stellar masses log 10 ( M * / M ⊙ ) ≈ 9 – 10 and decreases to < 20 % at log 10 ( M * / M ⊙ ) ∼ 10.7 . At higher stellar masses, however, the trend reverses, although this is likely due to active galactic nucleus contamination. We derive star formation rates (SFR) and specific SFR (sSFR) from the inferred Hα equivalent widths of our “Hα excess” galaxies. We show, for the first time, that the “Hα excess” galaxies clearly have a bimodal distribution on the SFR–M* plane: they lie on the main sequence of star formation (with log 10 ( sSFR / yr − 1 ) < − 8.05 ) or in a starburst cloud (with log 10 ( sSFR / yr − 1 ) > − 7.60 ). The latter contains ∼ 15 % of all the objects in our sample and accounts for > 50 % of the cosmic SFR density at z = 3.9 – 4.9 , for which we derive a robust lower limit of 0.066 M ⊙ yr − 1 Mpc − 3 . Finally, we identify an unusual > 50 σ overdensity of z = 3.9 – 4.9 galaxies within a 0.20 × 0.20 arcmin2 region. We conclude that the SMUVS unique combination of area and depth at mid-IR wavelengths provides an unprecedented level of statistics and dynamic range that are fundamental to revealing new aspects of galaxy evolution in the young universe.
Saturn's low‐latitude boundary layer: 1. Properties and variability

Transport of solar wind plasma into a planetary magnetosphere produces an internal boundary layer adjacent to the magnetopause that contains a mixture of solar wind and magnetospheric plasma. The potential processes responsible for this transport are varied, and their relative importance remains unclear, as well as how their competition varies between the magnetized planets. In this paper we examine the properties and variability of Saturn's low-latitude boundary layer (LLBL) using observations made by the Cassini spacecraft; the electron structure of Saturn's LLBL is examined in a companion paper. The duration of spacecraft excursions into the LLBL was generally between similar to 3 and similar to 23 min, and the electron environment of Saturn's LLBL was intermediate between that of the magnetosheath and that of the magnetosphere, as expected. Estimates of the speed of the magnetopause current layer are of the order of 100 km s (1), and the estimated thickness of the LLBL is of the order of 1 Saturn radius. Our results do not reveal a strong influence of the orientation of the interplanetary magnetic field on the thickness of Saturn's LLBL, which is unlike its terrestrial counterpart. There is also no clear dawn-dusk asymmetry in the thickness of Saturn's LLBL, which might be expected on the basis of our understanding of the growth of the Kelvin-Helmholtz instability at Saturn's magnetopause. We discuss the implications of these findings for the physics of Saturn's magnetospheric boundary and what this could mean for our understanding of how boundary layers are formed in planetary magnetospheres.
Valence quark contributions for the $\gamma^\ast N \to N(1440)$ form factors from light-front holography

The structure of the nucleon and the first radial excitation of the nucleon, the Roper, $N(1440)$, is studied within the formalism of Light-Front holography. The nucleon elastic form factors and $\gamma^\ast N \to N(1440)$ transition form factors are calculated under the assumption of the dominance of the valence quark degrees of freedom. Contrary to the previous studies, the bare parameters of the model associated with the valence quark are fixed by the empirical data for large momentum transfer ($Q^2$) assuming that the corrections to the three-quark picture (meson cloud contributions) are suppressed. The $\gamma^\ast N \to N(1440)$ transition form factors are then calculated without any adjustable parameters. Our estimates are compared with results from models based on valence quarks and others. The model compares well with the $\gamma^\ast N \to N(1440)$ transition form factor data, suggesting that meson cloud effects are not large, except in the region $Q^2< 1.5$ GeV$^2$. In particular, the meson cloud contributions for the Pauli form factor are small.
The ASAS-SN catalogue of variable stars III: variables in the southern TESS continuous viewing zone

The All-Sky Automated Survey for Supernovae (ASAS-SN) provides long baseline (${\sim}4$ yrs) light curves for sources brighter than V$\lesssim17$ mag across the whole sky. The Transiting Exoplanet Survey Satellite (TESS) has started to produce high-quality light curves with a baseline of at least 27 days, eventually for most of the sky. The combination of ASAS-SN and TESS light curves probes both long and short term variability in great detail, especially towards the TESS continuous viewing zones (CVZ) at the ecliptic poles. We have produced ${\sim}1.3$ million V-band light curves covering a total of ${\sim}1000 \, \rm deg^2$ towards the southern TESS CVZ and have systematically searched these sources for variability. We have identified ${\sim} 11,700$ variables, including ${\sim} 7,000$ new discoveries. The light curves and characteristics of the variables are all available through the ASAS-SN variable stars database (this https URL). We also introduce an online resource to obtain pre-computed ASAS-SN V-band light curves (this https URL) starting with the light curves of the ${\sim}1.3$ million sources studied in this work. This effort will be extended to provide ASAS-SN light curves for ${\sim}50\;$million sources over the entire sky.
Processing route for size distribution narrowing of ion beam synthesized nanoclusters

Ion beam synthesis of nanocrystals is explored using a recently developed kinetic Monte Carlo model for the process. The model suggests that temperature can be used to engineer nanocrystal size distributions. Specifically, by initiating implants at low temperature and then ramping the temperature upward, one can both tune the average size of the nanocrystals and restrict size distribution widths to less than 20% of the average size.
Sub-arcsecond Kinematic Structure of the Outflow in the Vicinity of the Protostar in L483

The bipolar outflow associated with the Class 0 low-mass protostellar source (IRAS 18148–0440) in L483 has been studied in the CCH and CS line emission at 245 and 262 GHz, respectively. Sub-arcsecond resolution observations of these lines have been conducted with ALMA. Structures and kinematics of the outflow cavity wall are investigated in the CS line, and are analyzed by using a parabolic model of an outflow. We constrain the inclination angle of the outflow to be from 75° to 90°, i.e., the outflow is blowing almost perpendicular to the line of sight. Comparing the outflow parameters derived from the model analysis with those of other sources, we confirm that the opening angle of the outflow and the gas velocity on its cavity wall correlate with the dynamical timescale of the outflows. Moreover, a hint of a rotating motion of the outflow cavity wall is found. Although the rotation motion is marginal, the specific angular momentum of the gas on the outflow cavity wall is evaluated to be comparable to or twice that of the infalling-rotating envelope of L483.