Miracle-dz/UniFAR-FTUs huggingface dataset:
Designing a template bank to observe compact binary coalescences in Advanced LIGO's second observing run

We describe the methodology and novel techniques used to construct a set of waveforms, or template bank, applicable to searches for compact binary coalescences in Advanced LIGO's second observing run. This template bank is suitable for observing systems composed of two neutron stars, two black holes, or a neutron star and a black hole. The Post-Newtonian formulation is used to model waveforms with total mass less than 4 $M_{\odot}$ and the most recent effective-one-body model, calibrated to numerical relativity to include the merger and ringdown, is used for total masses greater than 4 $M_{\odot}$. The effects of spin precession, matter, orbital eccentricity and radiation modes beyond the quadrupole are neglected. In contrast to the template bank used to search for compact binary mergers in Advanced LIGO's first observing run, here we are including binary-black-hole systems with total mass up to several hundreds of solar masses, thereby improving the ability to observe such systems. We introduce a technique to vary the starting frequency of waveform filters so that our bank can simultaneously contain binary-neutron-star and high-mass binary-black hole waveforms. We also introduce a lower-bound on the filter waveform length, to exclude very short-duration, high-mass templates whose sensitivity is strongly reduced by the characteristics and performance of the interferometers.
Robust synchronization via maximal monotone couplings

—We explore the use of set-valued coupling laws for the design of robust synchronized behaviors in networks of dynamical systems. Under an incremental dissipativity context, it is shown that coupling systems via maximal monotone mappings leads to synchronization that is robust against matched disturbances. Additionally, it is shown that perfect synchronization of heterogeneous networks with persistent matched disturbances is attained with ﬁnite coupling strength but inﬁnite incremental gain on the coupling maps. The real-life implementation of the proposed controllers is studied under the context of practical synchronization via Yosida regularizations. Simulations illustrate the effectiveness of the proposed methods.
Short gamma-ray burst central engines

Growing evidence connects the progenitor systems of the short-hard subclass of gamma-ray bursts (GRBs) to the merger of compact object binaries composed of two neutron stars (NSs) or of an NS and a black hole (BH). The recent observation of the binary NS (BNS) merger event GW170817 associated with GRB 170817A brought a great deal of additional information and provided further support to the above connection, even though the identification of this burst as a canonical short GRB (SGRB) remains uncertain. Decades of observational constraints and theoretical models consolidated the idea of a jet origin for the GRB prompt emission, which can also explain the multiwavelength afterglow radiation observed in most of the events. However, the mechanisms through which a BNS or NS–BH merger remnant would power a collimated outflow are much less constrained. Understanding the properties of the remnant systems and whether they can provide the right conditions for jet production has been a main driver of the great effort devoted to study BNS and NS–BH mergers, and still represents a real challenge from both the physical and the computational points of view. One fundamental open question concerns the nature of the central engine itself. While the leading candidate system is a BH surrounded by a massive accretion disk, the recent observation of plateau-shaped X-ray afterglows in some SGRBs would suggest a longer-lived engine, i.e. a metastable (or even stable) massive NS, which would also exclude NS–BH progenitors. Here we elaborate on this key aspect, considering three different scenarios to explain the SGRB phenomenology based on different hypotheses on the nature of the merger remnant. Then, we discuss the basic properties of GRB 170817A and how this event would fit within the different frameworks of the above scenarios, under the assumption that it was or was not a canonical SGRB.
SPHERE: the exoplanet imager for the Very Large Telescope

Observations of circumstellar environments that look for the direct signal of exoplanets and the scattered light from disks have significant instrumental implications. In the past 15 years, major developments in adaptive optics, coronagraphy, optical manufacturing, wavefront sensing, and data processing, together with a consistent global system analysis have brought about a new generation of high-contrast imagers and spectrographs on large ground-based telescopes with much better performance. One of the most productive imagers is the Spectro-Polarimetic High contrast imager for Exoplanets REsearch (SPHERE), which was designed and built for the ESO Very Large Telescope (VLT) in Chile. SPHERE includes an extreme adaptive optics system, a highly stable common path interface, several types of coronagraphs, and three science instruments. Two of them, the Integral Field Spectrograph (IFS) and the Infra-Red Dual-band Imager and Spectrograph (IRDIS), were designed to efficiently cover the near-infrared range in a single observation for an efficient search of young planets. The third instrument, ZIMPOL, was designed for visible polarimetric observation to look for the reflected light of exoplanets and the light scattered by debris disks. These three scientific instruments enable the study of circumstellar environments at unprecedented angular resolution, both in the visible and the near-infrared. In this work, we thoroughly present SPHERE and its on-sky performance after four years of operations at the VLT.
K-band luminosity (mass) segregation in AC118 at z=0.31

Using new observations of the galaxy cluster A118 at intermediate redshift (z=0.31) in the Ks band, we were able to detect the cluster from the center to half the Abell radius (1.5 Mpc, Ho=50 km/s/Mpc) and possibly to 2.0 Mpc. The analysis of both the spatial distribution of galaxies of various luminosities and of the luminosity function (LF) of galaxies in different cluster locations strongly confirms and extends to larger clustercentric radii the luminosity segregation found in a previous analysis of this cluster restricted to a smaller cluster area: there is an excess of bright galaxies in the cluster core (inside 250 Kpc) or a deficit of dwarfs in the remain part of the cluster. Outside the cluster core and as far as 1.5 or even 2 Mpc, the giant-to-dwarf ratio is constant. Because of the luminosity segregation, the LF of the AC118 shows a larger number of bright galaxies per unit dwarf in the core than in other cluster locations. All non-core LFs, computed at several cluster locations, are compatible each other. These results hold both including or excluding the galaxies located in an overdensity found in the far South of AC118 and in the second clump in galaxy density at the cluster North-West. Since the near-infrared emission is a good tracer of the stellar mass, we interpret the segregation found as a mass segregation.
Tip vortex cavitation on an oscillating hydrofoil

We discuss tests conducted in the hydrodynamic tunnel of the University of Grenoble on a 3D oscillating hydrofoil. Visualization of unsteady tip vortex cavitation indicates a strong influence of the water nuclei content. The investigation was focused on the influence of the oscillation frequency on tip vortex cavitation inception. For very low nuclei content, cavitation inception is strongly delayed as compared to the steady-state results at very small oscillation frequencies. This delay is significantly reduced by nuclei seeding. The results can be explained by assuming that the time required for the inception of cavitation in the tip vortex corresponds to the time necessary for a cavitation nucleus to be captured by the vortex core
Relationship of First- to Second-Order Transition Temperatures for Crystalline High Polymers

This paper concerns an empirical linear relationship between the melting temperature T1 and the second‐order or glassy transition temperature T2 for partially crystalline polymers. Two lines can be drawn, one for symmetrical polymers, the other for unsymmetrical polymers, the latter being of lower slope. These families are only approximate. It is shown for a limited group of polymers, that T2 is proportional to the cohesive energy density of the polymer. Since T1=ΔH/ΔS, it is suggested that the two families of curves arise because of differences in ΔS which depends on symmetry and chain stiffness. It is shown that T1 and T2 are linearly related with diluent as a common parameter.
Efficient discrete Gabor functions for robot vision

A new discrete Gabor function provides subpixel resolution of phase while overcoming many of the computational burdens of current approaches to Gabor function implementation. Applications include hyperacuity measurement of binocular disparity and optic flow for stereo vision. Convolution is avoided by exploiting band-pass to subsample the image plane. A general purpose front end processor for robot vision, based on a wavelet interpretation of this discrete Gabor function, can be constructed by tessellating and pyramiding the elementary filter. Computational efficiency opens the door to real-time implementation which mimics many properties of the simple and complex cells in the visual cortex.
Positron annihilation in the positronium negative ion

A theoretical study of positronium negative ions is carried out. Hylleraas-type wavefunctions are employed to describe the system and an improved ground-state energy is reported. In addition, the two-photon annihilation rate and the lifetime against two-photon annihilation are also calculated, as well as the two-photon angular correlation function.
Sampling-Based Motion Planning With Differential Constraints

Since differential constraints which restrict admissible velocities and accelerations of robotic systems are ignored in path planning, solutions for kinodynamic and non-holonomic planning problems from classical methods could be either inexecutable or inefficient. Motion planning with differential constraints (MPD), which directly considers differential constraints, provides a promising direction to calculate reliable and efficient solutions. A large amount of recent efforts have been devoted to various sampling-based MPD algorithms, which iteratively build search graphs using sampled states and controls. This thesis addresses several issues in analysis and design of these algorithms. Firstly, resolution completeness of path planning is extended to MPD and the first quantitative conditions are provided. The analysis is based on the relationship between the reachability graph, which is an intrinsic graph representation of a given problem, and the search graph, which is built by the algorithm. Because of sampling and other complications, there exist mismatches between these two graphs. If a solution exists in the reachability graph, resolution complete algorithms must construct a solution path encoding the solution or its approximation in the search graph in finite time. Secondly, planners are improved with symmetry-based gap reduction algorithms to solve their gap problem, which dramatically increases time to return a high quality solution trajectory whose final state is in a small neighborhood of a goal state. The improved planners quickly obtain high quality solutions by minimizing gaps in solution path candidates, which is greatly accelerated using symmetries of robotic systems to avoid numerical integration. Finally, a heuristic is designed to solve metric sensitivity of RRT-based planners, which means that RRT-based methods have difficulties in escaping local minima when the given metric provides a poor approximation of the cost-to-go. Instead of designing a metric, the heuristic is obtained by collecting collision information online and assigning a real value to each node in the search graph. A node with a higher value means that the number of trajectories from the node that have been detected in collision is larger. Local minima are more likely to be avoided when nodes with smaller values are given higher probability to be extended.
Transport in bilayer graphene: Calculations within a self-consistent Born approximation

The transport properties of a bilayer graphene are studied theoretically within a self-consistent Born approximation. The electronic spectrum is composed of $k$-linear dispersion in the low-energy region and $k$-square dispersion as in an ordinary two-dimensional metal at high energy, leading to a crossover between different behaviors in the conductivity on changing the Fermi energy or disorder strengths. We find that the conductivity approaches $2{e}^{2}∕{\ensuremath{\pi}}^{2}\ensuremath{\hbar}$ per spin in the strong-disorder regime, independently of the short- or long-range disorder.
On KdV characters in large c CFTs

Two-dimensional conformal ﬁeld theories with just Virasoro symmetry are endowed with integrable structure. We review how to construct the integrable charges in a two-dimensional conformal ﬁeld theory and how to relate them to the charges of quantum Sinh-Gordon theory when c ≥ 25 . We then explicitly calculate the single charge characters in the large c limit for all charges and thereby reveal how their degeneracies grow within one module. This, in particular, allows us to approximate the characters in the limit of small chemical potential, which source the respective charges. The latter give us insights into possible transformation properties of the characters. We also comment on the full generalized Gibbs ensemble and approximations to pure states.
Yb-doped all fiber picosecond laser based on grade-index multimode fiber with microcavity.

We demonstrate an all-fiber mode-locked laser at all-normal dispersion with a saturable absorber, which is based on a section of grade-index multimode fiber with inner microcavity embedded in the splice points. The absorption modulation depth of this nonlinear saturable absorber is 2.2% in the suitable bent state. The fiber laser operates at central wavelength of 1035nm with average power of ~1.26mW, pulse-duration of 17.05 ps, repetition rate of 37.098MHz. This kind of saturable absorber has superiorities of low cost, high stability and high damage threshold, which may facilitate applications in optical sensing, material processing and light detection.
Multi-Community Detection in Signed Graphs Using Quantum Hardware

Signed graphs serve as a primary tool for modelling social networks. They can represent relationships between individuals (i.e., nodes) with the use of signed edges. Finding communities in a signed graph is of great importance in many areas, for example, targeted advertisement. We propose an algorithm to detect multiple communities in a signed graph. Our method reduces the multi-community detection problem to a quadratic binary unconstrained optimization problem and uses state-of-the-art quantum or classical optimizers to find an optimal assignment of each individual to a specific community.
RXTE Observations of 1A 1744–361: Correlated Spectral and Timing Behavior

We analyze Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) data of the transient low-mass X-ray binary (LMXB) system 1A 1744-361. We explore the X-ray intensity and spectral evolution of the source, perform timing analysis, and find that 1A 1744-361 shows "atoll" behavior during the outbursts. The color-color diagram indicates that this LMXB was observed in a low-intensity, spectrally hard (low-hard) state and in a high-intensity "banana" state. The low-hard state shows a horizontal pattern in the color-color diagram, and the previously reported "dipper QPO" appears only during this state. We also perform energy spectral analyses, and report the first detection of a broad iron emission line and an iron absorption edge from 1A 1744-361.
The Possible z = 0.83 Precursors of z = 0, M* Early-Type Cluster Galaxies

We examine the distribution of stellar masses of galaxies in MS 1054.4-0321 and Cl 0152.7-1357, two X-ray-selected clusters of galaxies at z = 0.83. Our stellar mass estimates, from spectral energy distribution fitting, reproduce the dynamical masses as measured from velocity dispersions and half-light radii with a scatter of 0.2 dex in the mass for early-type galaxies. When we restrict our sample of members to high stellar masses, those over 1011.1 M☉ (M* in the Schechter mass function for cluster galaxies), we find that the fraction of early-type galaxies is 79% ± 6% at z = 0.83 and 87% ± 6% at z = 0.023 for the Coma Cluster, consistent with no evolution. Previous work with luminosity-selected samples has found that the early-type fraction in rich clusters declines from ≃80% at z = 0 to ≃60% at z = 0.8. The observed evolution in the early-type fraction from luminosity-selected samples must predominantly occur among sub-M* galaxies. As M* for field and group galaxies, especially late types, is below M* for cluster galaxies, infall could explain most of the recent growth in the early-type fraction. Future surveys could determine the morphological distributions of lower mass systems, which would confirm or refute this explanation.
The 85Kr s-Process Branching and the Mass of Carbon Stars

We present new spectroscopic observations for a sample of C(N)-type red giants. These objects belong to the class of asymptotic giant branch stars, experiencing thermal instabilities in the He-burning shell (thermal pulses). Mixing episodes called third dredge-up enrich the photosphere with newly synthesized 12C in the He-rich zone, and this is the source of the high observed ratio between carbon and oxygen (C/O ≥ 1 by number). Our spectroscopic abundance estimates confirm that, in agreement with the general understanding of the late evolutionary stages of low- and intermediate-mass stars, carbon enrichment is accompanied by the appearance of s-process elements in the photosphere. We discuss the details of the observations and of the derived abundances, focusing in particular on rubidium, a neutron density sensitive element, and on the s-elements Sr, Y, and Zr belonging to the first s-peak. The critical reaction branching at 85Kr, which determines the relative enrichment of the studied species, is discussed. Subsequently, we compare our data with recent models for s-processing in thermally pulsing asymptotic giant branch stars, at metallicities relevant for our sample. A remarkable agreement between model predictions and observations is found. Thanks to the different neutron density prevailing in low- and intermediate-mass stars, comparison with the models allows us to conclude that most C(N) stars are of low mass (M ≲ 3 M☉). We also analyze the 12C/13C ratios measured, showing that most of them cannot be explained by canonical stellar models. We discuss how this fact would require the operation of an ad hoc additional mixing, currently called cool bottom process, operating only in low-mass stars during the first ascent of the red giant branch and, perhaps, also during the asymptotic giant branch.
A Comprehensive Study of $g$-Factors, Elastic, Structural and Electronic Properties of III-V Semiconductors using Hybrid-Density Functional Theory

Despite the large number of theoretical III-V semiconductor studies reported every year, our atomistic understanding is still limited. The limitations of the theoretical approaches to yield accurate structural and electronic properties on an equal footing, due to the unphysical self-interaction problem that affects mainly the band gap and spin-orbit splitting (SOC) in semiconductors and, in particular, III-V systems with similar magnitude of the band gap and SOC. In this work, we will report a consistent study of the structural and electronic properties of the III-V semiconductors employing the screening hybrid-DFT framework, fitting the $\alpha$ parameters for 12 different III-V compounds, namely, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, in order to minimize the deviation between the theoretical and experimental values of the band gap and SOC. Structural relaxation effects were also included. Except for AlP, whose $\alpha = 0.127$, we obtained $\alpha$ values spreading from 0.209 to 0.343, deviating less than 0.1 from the universal value of 0.25. Our results for the lattice parameter and elastic constants indicate that the fitting of the $\alpha$ does not affect those structural parameters when compared with the HSE06 functional, where $\alpha = 0.25$. Our analysis of the band structure based on the $\textbf{k}{\cdot}\textbf{p}$ method shows that the effective masses are in agreement with the experimental values, which can be attributed to the simultaneous fitting of the band gap and SOC. Finally, we estimate the values of $g$-factors, extracted directly from band structure, which are close to experimental results indicating that the obtained band structure produced a realistic set of $\textbf{k}{\cdot}\textbf{p}$ parameters.
In-depth study of long-term variability in the X-ray emission of the Be/X-ray binary system AX J0049.4−7323

AX J0049.4−7323 is a Be/X-ray binary in the Small Magellanic Cloud hosting a ~750 s pulsar which has been observed over the last ~17 years by several X-ray telescopes. Despite numerous observations, little is known about its X-ray behaviour. Therefore, we coherently analysed archival Swift, Chandra, XMM-Newton, RXTE, and INTEGRAL data, and we compared them with already published ASCA data, to study its X-ray long-term spectral and flux variability. AX J0049.4−7323 shows a high X-ray variability, spanning more than three orders of magnitudes, from L ≈ 1.6 × 1037 erg s−1 (0.3−8 keV, d = 62 kpc) down to L ≈ 8 × 1033 erg s−1. RXTE, Chandra, Swift, and ASCA observed, in addition to the expected enhancement of X-ray luminosity at periastron, flux variations by a factor of ~270 with peak luminosities of ≈2.1 × 1036 erg s−1 far from periastron. These properties are difficult to reconcile with the typical long-term variability of Be/XRBs, traditionally interpreted in terms of type I and type II outbursts. The study of AX J0049.4−7323 is complemented with a spectral analysis of Swift, Chandra, and XMM-Newton data which showed a softening trend when the emission becomes fainter, and an analysis of optical/UV data collected by the UVOT telescope on board Swift. In addition, we measured a secular spin-up rate of Ṗ = (−3.00 ± 0.12) × 10−3 s day−1, which suggests that the pulsar has not yet achieved its equilibrium period. Assuming spherical accretion, we estimated an upper limit for the magnetic field strength of the pulsar of ≈3 × 1012 G.
Dissipation and vortex creation in Bose-Einstein condensed gases

We solve the Gross-Pitaevskii equation to study energy transfer from an oscillating `object' to a trapped Bose-Einstein condensate. Two regimes are found: for object velocities below a critical value, energy is transferred by excitation of phonons at the motion extrema; while above the critical velocity, energy transfer is via vortex formation. The second regime corresponds to significantly enhanced heating, in agreement with a recent experiment.