Miracle-dz/UniFAR-FTUs huggingface dataset:
EXTREMELY SOFT X-RAY FLASH AS THE INDICATOR OF OFF-AXIS ORPHAN GRB AFTERGLOW

We verified the off-axis jet model of X-ray flashes (XRFs) and examined a discovery of off-axis orphan gamma-ray burst (GRB) afterglows. The XRF sample was selected on the basis of the following three factors: (1) a constraint on the lower peak energy of the prompt spectrum E obs src ? > , (2) redshift measurements, and (3) multicolor observations of an earlier (or brightening) phase. XRF 020903 was the only sample selected on the basis of these criteria. A complete optical multicolor afterglow light curve of XRF 020903 obtained from archived data and photometric results in the literature showed an achromatic brightening around 0.7 days. An off-axis jet model with a large observing angle (0.21 rad, which is twice the jet opening half-angle, θ jet ? > ) can naturally describe the achromatic brightening and the prompt X-ray spectral properties. This result indicates the existence of off-axis orphan GRB afterglow light curves. Events with a larger viewing angle ( > ∼ 2 θ jet ? > ) could be discovered using an 8 m class telescope with wide-field imagers such as the Subaru Hyper-Suprime-Cam and the Large Synoptic Survey Telescope.
Renormalized spectral function for Co adatom on the Pt(111) surface

The strong Coulomb correlations effects in the electronic structure of magnetic Co adatom on the Pt(111) surface have been investigated. Using a realistic five d-orbital impurity Anderson model at low temperatures with parameters determined from first-principles calculations we found a striking change of the electronic structure in comparison with the LDA results. The spectral function calculated with full rotationally invariant Coulomb interaction is in good agreement with the quasiparticle region of the STM conductance spectrum. Using the calculated spin-spin correlation functions we have analyzed the formation of the magnetic moments of the Co impurity orbitals.
MONTE CARLO SIMULATIONS OF GLOBULAR CLUSTER EVOLUTION. VI. THE INFLUENCE OF AN INTERMEDIATE-MASS BLACK HOLE

We present results from a series of Monte Carlo (MC) simulations investigating the imprint of a central intermediate-mass black hole (IMBH) on the structure of a globular cluster. We investigate the three-dimensional and projected density profiles, and stellar disruption rates for idealized as well as realistic cluster models, taking into account a stellar mass spectrum and stellar evolution, and allowing for a larger, more realistic number of stars than was previously possible with direct N-body methods. We compare our results to other N-body and Fokker–Planck simulations published previously. We find, in general, very good agreement for the overall cluster structure and dynamical evolution between direct N-body simulations and our MC simulations. Significant differences exist in the number of stars that are tidally disrupted by the IMBH, and this is most likely caused by the wandering motion of the IMBH, not included in the MC scheme. These differences, however, are negligible for the final IMBH masses in realistic cluster models, as the disruption rates are generally much lower than for single-mass clusters. As a direct comparison to observations we construct a detailed model for the cluster NGC 5694, which is known to possess a central surface brightness cusp consistent with the presence of an IMBH. We find that not only the inner slope but also the outer part of the surface brightness profile agree well with observations. However, there is only a slight preference for models harboring an IMBH compared to models without.
Multiple stellar populations in the globular cluster NGC 1851

[Abridged] Detailed chemical tagging of individual stellar populations in the Galactic globular cluster (GC) NGC 1851 is presented. Abundances are derived from FLAMES spectra for the largest sample of giants (124) ever analysed in this peculiar GC using O, Na, Mg, Al, Si, Ca, Ti, Sc, V, Mn, Co, Ni, Cu, Y, Zr, Ba, La, Ce, Nd, Eu, Dy. We confirm a [Fe/H] spread in this GC, but too small to clearly separate different sub-populations. We instead propose a classification using a combination of Fe and Ba (much more abundant in the more metal-rich group) through a cluster analysis: we separated stars into a metal-rich (MR) and a metal-poor (MP) populations, each of them showing a Na-O anticorrelation, signature of genuine GC, although with different ratios of primordial to polluted stars. The ratio [alpha/H] tracks iron and is higher in the MR population, suggesting an additional contribution by core-collapse supernovae. The MR population shows a larger enrichment in s-process elements compared to the MP one. This is probably due to the contribution by intermediate-low mass stars, because we find that the level of heavy s-process elements is larger than the level of light s-process nuclei in the MR stars; however, a large contribution by low mass stars is unlikely, because it would likely cancel the O-Na anticorrelation. We also confirm the presence of correlations between p-capture and s-process elements previously found by other studies, at least for the MR population. This finding apparently requires a quite long delay for the second generation of the MR component. A merger of two distinct GCs in a parent dwarf galaxy, each one with a different Ba level and an age difference of ~1 Gyr, might explain (i) the double SGB, (ii) a possible difference in C content between the two original GCs, and (iii) the Stromgren photometry of this peculiar GC.
Ibadan Lectures on Toric Varieties

Toric varieties are perhaps the most accessible class of algebraic varieties. They often arise as varieties parameterized by monomials, and their structure may be completely understood through objects from geometric combinatorics. While accessible and understandable, the class of toric varieties is also rich enough to illustrate many properties of algebraic varieties. Toric varieties are also ubiquitous in applications of mathematics, from tensors to statistical models to geometric modeling to solving systems of equations, and they are important to other branches of mathematics such as geometric combinatorics and tropical geometry. These notes are based on, and significantly extend, Frank Sottile's short course of four lectures at the CIMPA school on Combinatorial and Computational Algebraic Geometry in Ibadan, Nigeria 12--23 June 2017.
Extremal Rays and Nefness of Tangent Bundles

In view of Mori theory, rational homogenous manifolds satisfy a recursive condition: every elementary contraction is a rational homogeneous fibration and the image of any elementary contraction also satisfies the same property. In this paper, we show that a smooth Fano $n$-fold with the same condition and Picard number greater than $n-6$ is either a rational homogeneous manifold or the product of $n-7$ copies of $\mathbb{P}^1$ and a Fano $7$-fold $X_0$ constructed by G. Ottaviani. We also clarify that $X_0$ has non-nef tangent bundle and in particular is not rational homogeneous.
Two loop stress-energy tensor for inflationary scalar electrodynamics

We calculate the expectation value of the coincident product of two field strength tensors at two loop order in scalar electrodynamics on de Sitter background. The result agrees with the stochastic formulation which we have developed in a companion paper [T. Prokopec, N. C. Tsamis, and R. P. Woodard, Ann. Phys. (N.Y.) 323, 1324 (2008)] for the nonperturbative resummation of leading logarithms of the scale factor. When combined with a previous computation of scalar bilinears [T. Prokopec, N. C. Tsamis, and R. P. Woodard, Classical Quantum Gravity 24, 201 (2007)], our current result also gives the two loop stress-energy tensor for inflationary scalar electrodynamics. This shows a secular decrease in the vacuum energy which derives from the vacuum polarization induced by the inflationary production of charged scalars.
Compact binary merger and kilonova: outflows from remnant disc

Outflows launched from a remnant disc of compact binary merger may have essential contribution to the kilonova emission. Numerical calculations are conducted in this work to study the structure of accretion flows and outflows. By the incorporation of limited-energy advection in the hyper-accretion discs, outflows occur naturally from accretion flows due to imbalance between the viscous heating and the sum of the advective and radiative cooling. Following this spirit, we revisit the properties of the merger outflow ejecta. Our results show that around $10^{-3} \sim 10^{-1} M_\odot$ of the disc mass can be launched as powerful outflows. The amount of unbound mass varies with the disc mass and the viscosity. The outflow-contributed peak luminosity is around $10^{40} \sim 10^{41}$ erg/s. Such a scenario can account for the observed kilonovae associated with short gamma-ray bursts, including the recent event AT2017gfo (GW170817).
Twistor actions for gauge theory and gravity

This is a review of recent developments in the study of perturbative gauge theory and gravity using action functionals on twistor space. It is intended to provide a user-friendly introduction to twistor actions, geared towards researchers or graduate students interested in learning something about the utility, prospects, and shortcomings of this approach. For those already familiar with the twistor approach, it should provide a condensed overview of the literature as well as several novel results of potential interest. This work is based primarily upon the author's D.Phil. thesis. We first consider four-dimensional, maximally supersymmetric Yang-Mills theory as a gauge theory in twistor space. We focus on the perturbation theory associated to this action, which in an axial gauge leads to the MHV formalism. This allows us to efficiently compute scattering amplitudes at tree-level (and beyond) in twistor space. Other gauge theory observables such as local operators and null polygonal Wilson loops can also be formulated twistorially, leading to proofs for several correspondences between correlation functions and Wilson loops, as well as a recursive formula for computing mixed Wilson loop / local operator correlators. We then apply the twistor action approach to general relativity, using the on-shell equivalence between conformal and Einstein gravity. This can be extended to N=4 supersymmetry. The perturbation theory of the twistor action leads to formulae for the MHV amplitude with and without cosmological constant, yields a candidate for the Einstein twistor action, and induces a MHV formalism on twistor space. Appendices include discussion of super-connections and Coulomb branch regularization on twistor space.
Four-Round Black-Box Non-Malleable Commitments from One-Way Permutations

We construct the first four-round non-malleable commitment scheme based solely on the black-box use of one-to-one one-way functions. Prior to our work, all non-malleable commitment schemes based on black-box use of polynomial-time cryptographic primitives require more than 16 rounds of interaction. A key tool for our construction is a proof system that satisfies a new definition of security that we call non-malleable zero-knowledge with respect to commitments . In a nutshell, such a proof system can be safely run in parallel with a (potentially interactive) commitment scheme. We provide an instantiation of this tool using the MPC-in-the-Head approach in combination with BMR.
Anti-Lambda Polarization in High Energy pp Collisions with Polarized Beams

We study the polarization of the anti-Lambda particle in polarized high energy pp collisions at large transverse momenta. The anti-Lambda polarization is found to be sensitive to the polarization of the anti-strange sea of the nucleon. We make predictions using different parameterizations of the polarized quark distribution functions. The results show that the measurement of longitudinal anti-Lambda polarization can distinguish different parameterizations, and that similar measurements in the transversely polarized case can give some insights into the transversity distribution of the anti-strange sea of nucleon.
Shannon meets Carnot: Generalized second thermodynamic law

The classical thermodynamic laws fail to capture the behavior of systems with the energy Hamiltonian being an explicit function of the temperature. Such Hamiltonian arises, for example, in modeling information processing systems, like communication channels, as thermal systems. Here we generalize the second thermodynamic law to encompass systems with temperature-dependent energy levels, , where ⟨·⟩ denotes averaging over the Boltzmann distribution and reveal a new definition to the basic notion of temperature. Furthermore, it is shown that the principles of the traditional thermodynamic framework are maintained, e.g., two systems in equilibrium have the same generalized temperature and heat always flows from high to low generalized temperature. This generalization enables to express, for instance, the mutual information of the Gaussian channel as a consequence of the laws of nature —the laws of thermodynamics.
A simple model for the evolution of the dust population in protoplanetary disks

Context. The global size and spatial distribution of dust is an important ingredient in the structure and evolution of protoplanetary disks and in the formation of larger bodies, such as planetesimals. Aims. We aim to derive simple equations that explain the global evolution of the dust surface density profile and the upper limit of the grain size distribution and which can readily be used for further modeling or for interpreting of observational data. Methods. We have developed a simple model that follows the upper end of the dust size distribution and the evolution of the dust surface density profile. This model is calibrated with state-of-the-art simulations of dust evolution, which treat dust growth, fragmentation, and transport in viscously evolving gas disks. Results. We find very good agreement between the full dust-evolution code and the toy model presented in this paper. We derive analytical profiles that describe the dust-to-gas ratios and the dust surface density profiles well in protoplanetary disks, as well as the radial flux by solid material “rain out”, which is crucial for triggering any gravity assisted formation of planetesimals. We show that fragmentation is the dominating effect in the inner regions of the disk leading to a dust surface density exponent of −1.5, while the outer regions at later times can become drift-dominated, yielding a dust surface density exponent of −0.75. Our results show that radial drift is not efficient in fragmenting dust grains. This supports the theory that small dust grains are resupplied by fragmentation due to the turbulent state of the disk.
The geometry of thresholdless active flow in nematic microfluidics

"Active nematics" are orientationally ordered but apolar fluids composed of interacting constituents individually powered by an internal source of energy. When activity exceeds a system-size dependent threshold, spatially uniform active apolar fluids undergo a hydrodynamic instability leading to spontaneous macroscopic fluid flow. Here, we show that a special class of spatially non-uniform configurations of such active apolar fluids display laminar (i.e., time-independent) flow even for arbitrarily small activity. We also show that two-dimensional active nematics confined on a surface of non-vanishing Gaussian curvature must necessarily experience a non-vanishing active force. This general conclusion follows from a key result of differential geometry: geodesics must converge or diverge on surfaces with non-zero Gaussian curvature. We derive the conditions under which such curvature-induced active forces generate "thresholdless flow" for two-dimensional curved shells. We then extend our analysis to bulk systems and show how to induce thresholdless active flow by controlling the curvature of confining surfaces, external fields, or both. The resulting laminar flow fields are determined analytically in three experimentally realizable configurations that exemplify this general phenomenon: i) toroidal shells with planar alignment, ii) a cylinder with non-planar boundary conditions, and iii) a "Frederiks cell" that functions like a pump without moving parts. Our work suggests a robust design strategy for active microfluidic chips and could be tested with the recently discovered "living liquid crystals".
Monitoring evolved stars for binarity with the HERMES spectrograph

Binarity is often invoked to explain peculiarities that can not be explained by the standard theory of stellar evolution. Detecting orbital motion via the Doppler effect is the best method to test binarity when direct imaging is not possible. However, when the orbital period exceeds the duration of a typical observing run, monitoring often becomes problematic. Placing a high-throughput spectrograph on a small semi- robotic telescope allowed us to carry out a radial-velocity survey of various types of peculiar evolved stars. In this review we highlight some findings after the first four years of observations. Thus, we detect eccentric binaries among hot subdwarfs, barium, S stars, and post- AGB stars with disks, which are not predicted by the standard binary interaction theory. In disk objects, in addition, we find signs of the on- going mass transfer to the companion, and an intriguing line splitting, which we attribute to the scattered light of the primary.
A MAD view of Trumpler 14

We present adaptive optics (AO) near-infrared observations of the core of the Tr 14 cluster in the Carina region obtained with the ESO multi-conjugate AO demonstrator, MAD. Our campaign yields AO-corrected observations with an image quality of about 0.2 �� across the 2 � field of view, which is the widest AO mosaic ever obtained. We detected almost 2000 sources spanning a dynamic range of 10 mag. The pre-main sequence (PMS) locus in the colour−magnitude diagram is well reproduced by Palla & Stahler isochrones with an age of 3 to 5 × 10 5 yr, confirming the very young age of the cluster. We derive a very high (deprojected) central density n0 ∼ 4.5(±0.5) × 10 4 pc −3 and estimate the total mass of the cluster to be about ∼4.3 +3.3 −1.5 × 10 3 M � , although contamination of the field of view might have a significant impact on the derived mass. We show that the pairing process is largely dominated by chance alignment so that physical pairs are difficult to disentangle from spurious ones based on our single epoch observation. Yet, we identify 150 likely bound pairs, 30% of these with a separation smaller than 0.5 �� (∼1300 AU). We further show that at the 2σ level massive stars have more companions than lower-mass stars and that those companions are respectively brighter on average, thus more massive. Finally, we find some hints of mass segregation for stars heavier than about 10 M� . If confirmed, the observed degree of mass segregation could be explained by dynamical evolution, despite the young age of the cluster.
VIP-2 at LNGS: An experiment on the validity of the Pauli Exclusion Principle for electrons

We are experimentally investigating possible violations of standard quantum mechanics predictions in the Gran Sasso underground laboratory in Italy. We test with high precision the Pauli Exclusion Principle and the collapse of the wave function (collapse models). We present our method of searching for possible small violations of the Pauli Exclusion Principle (PEP) for electrons, through the search for “anomalous” X-ray transitions in copper atoms. These transitions are produced by “new” electrons (brought inside the copper bar by circulating current) which can have the possibility to undergo Pauli-forbidden transition to the 1s level already occupied by two electrons. We describe the VIP2 (VIolation of the Pauli Exclusion Principle) experimental data taking at the Gran Sasso underground laboratories. The goal of VIP2 is to test the PEP for electrons in agreement with the Messiah-Greenberg superselection rule with unprecedented accuracy, down to a limit in the probability that PEP is violated at the level of 10−31. We show preliminary experimental results and discuss implications of a possible violation.
A new characterization of convexity with respect to Chebyshev systems

The notion of $n$th order convexity in the sense of Hopf and Popoviciu is defined via the nonnegativity of the $(n+1)$st order divided differences of a given real-valued function. In view of the well-known recursive formula for divided differences, the nonnegativity of $(n+1)$st order divided differences is equivalent to the $(n-k-1)$st order convexity of the $k$th order divided differences which provides a characterization of $n$th order convexity. The aim of this paper is to apply the notion of higher-order divided differences in the context of convexity with respect to Chebyshev systems introduced by Karlin in 1968. Using a determinant identity of Sylvester, we then establish a formula for the generalized divided differences which enables us to obtain a new characterization of convexity with respect to Chebyshev systems. Our result generalizes that of W\k{a}sowicz which was obtained in 2006. As an application, we derive a necessary condition for functions which can be written as the difference of two functions convex with respect to a given Chebyshev system.
I2PA : An Efficient ABC for IoT

The Internet of Things (IoT) is very attractive because of its promises. However, it brings many challenges, mainly issues about privacy preservation and lightweight cryptography. Many schemes have been designed so far but none of them simultaneously takes into account these aspects. In this paper, we propose an efficient attribute-based credential scheme for IoT devices. We use elliptic curve cryptography without pairing, blind signing, and zero-knowledge proof. Our scheme supports block signing, selective disclosure, and randomization. It provides data minimization and transaction unlinkability. Our construction is efficient since smaller key size can be used, and computing time can be reduced. As a result, it is a suitable solution for IoT devices characterized by three major constraints, namely low-energy power, small storage capacity, and low computing power.
Bayesian comparison of non-standard cosmologies using type Ia supernovae and BAO data

We use the most recent type Ia supernovae (SNe Ia) observations to perform a statistical comparison between the standard $\Lambda$CDM model and its extensions ($w$CDM and $w(z)$CDM) and some alternative cosmologies, namely: the Dvali--Gabadadze--Porrati (DGP) model, a power-law $f(R)$ scenario in the metric formalism and an example of vacuum decay ($\Lambda(t)$CDM) cosmology in which the dilution of pressureless matter is attenuated with respect to the usual $a^{-3}$ scaling due to the interaction of the dark matter and dark energy fields. We perform a Bayesian model selection analysis using the Affine-Invariant Monte-Carlo Ensemble sampler. In order to obtain the posterior distribution for the parameters of each model, we use the Joint Lightcurve Analysis (JLA) SNe Ia compilation containing 740 events in the interval $0.01 < z < 1.3$. The data are analysed with the SALT-II light-curve fitter and the model selection is then performed by computing the Bayesian evidence of each model and the Bayes factor between them. The results indicate that the JLA data only cannot distinguish the standard $\Lambda$CDM from its alternatives but their combination with current measurements of baryon acoustic oscillations can. We provide a rank order for the models considered and also discuss the influence of the $H_0$ priors on the results.