Miracle-dz/UniFAR-FTUs huggingface dataset:
Transition from inspiral to plunge for braneworld EMRI

In the present article, we discuss the late inspiral and then the transition regime to the plunge phase of a secondary, less massive compact object into a more massive braneworld black hole, in the context of an extreme-mass-ratio inspiral. We obtain the approximate expressions for fluxes due to slowly evolving constants of motion, such as the energy and the angular momentum, in the presence of the tidal charge inherited from the higher spacetime dimensions for an extreme-mass-ratio system. These expressions for fluxes are further used to introduce dissipative effects while modelling the inspiral to the plunge phase through the transition regime. Within our setup, we provide a qualitative understanding of how the additional tidal charge present in the braneworld scenario may affect the timescale of the late inspiral to the plunge, in particular, by enhancing the time scale of the transition regime. Finally, we provide an estimate for the tidal charge from the higher dimensions, using the observable aspects of the transition regime from the late inspiral to the plunge by the gravitational wave detectors.
A Multiwavelength Study of the Ongoing Changing-look AGN AT2021fxu

We present multiwavelength analyses of an active optical transient AT2021fxu which shows the appearance of previously absent broad emission lines in a recent optical spectrum, suggesting a Changing-look Active Galactic Nucleus (AGN). During the spectral transition, the brightness in the individual photometric bands increased up to ≈0.6 in the optical bands and up to ≈1.1 mag in the UV bands. The brightening was accompanied by a blueward shift of the optical spectrum. AT2021fxu shows high X-ray (0.3–10 keV) flux variability before and after the outburst, with the average X-ray flux increasing by a factor of ≈2 post-outburst. However, the X-ray spectral shape remains roughly the same, with no significant change in the line-of-sight column density. AT2021fxu’s overall properties are consistent with an accretion-rate-driven transition from a Type-II to a Type-1 AGN.
Fast Outflowing Warm Absorbers in Narrow-line Seyfert 1 Galaxy PG 1001+054 Revealed by HST/COS Spectra

Narrow-line Seyfert 1 (NLS1) galaxies are an important type of active galactic nucleus (AGN), generally expected to be accreting at a high Eddington rate. The properties of their outflows and importance of AGN feedback remain intriguing. We report on the discovery of fast outflowing warm absorbers (WAs) in the NLS1 PG 1001+054 with velocities in the range of ∼7000–9000 km s−1. They are identified with blueshifted Lyα, N v, and Si iv lines in the high-resolution ultraviolet (UV) spectra taken with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. We perform photoionization modeling using XSTAR with three WAs. The derived physical properties are typical of WAs in terms of ionization and column density, whereas the outflow velocities are significantly higher. The estimated location of these WAs ranges from 1 to 73 parsecs away from the AGN. Together with previous detection of high ionization absorbers in the X-ray for PG 1001+054, we suggest that fast outflowing UV absorbers are probably part of a multiphase outflow. Such a structure is likely produced by the outflow launched from the AGN at an accretion disk scale, which shocks the ambient interstellar medium (ISM), producing stratified absorbers. Assuming contribution from the three WAs at tens of parsecs, the estimated ratio between the kinetic power of the outflow and AGN Eddington luminosity could reach 1.7%, raising the possibility of sufficient influence on the host galaxy when compared to some theoretical models for efficient AGN feedback.
A new approach and code for spinning black holes in modified gravity

We discuss and implement a spectral method approach to computing stationary and axisymmetric black hole solutions and their properties in modified theories of gravity. The resulting code is written in the Julia language and is transparent and easily adapted to new settings. We test the code on both general relativity and on Einstein-scalar-Gauss–Bonnet gravity. It is accurate and fast, converging on a spinning solution in these theories with tiny errors ( in most cases) in a matter of seconds.
Fast and Provably Convergent Algorithms for Gromov-Wasserstein in Graph Data

In this paper, we study the design and analysis of a class of efficient algorithms for computing the Gromov-Wasserstein (GW) distance tailored to large-scale graph learning tasks. Armed with the Luo-Tseng error bound condition~\citep{luo1992error}, two proposed algorithms, called Bregman Alternating Projected Gradient (BAPG) and hybrid Bregman Proximal Gradient (hBPG) enjoy the convergence guarantees. Upon task-specific properties, our analysis further provides novel theoretical insights to guide how to select the best-fit method. As a result, we are able to provide comprehensive experiments to validate the effectiveness of our methods on a host of tasks, including graph alignment, graph partition, and shape matching. In terms of both wall-clock time and modeling performance, the proposed methods achieve state-of-the-art results.
Learning particle swarming models from data with Gaussian processes

Interacting particle or agent systems that exhibit diverse swarming behaviors are prevalent in science and engineering. Developing effective differential equation models to understand the connection between individual interaction rules and swarming is a fundamental and challenging goal. In this paper, we study the data-driven discovery of a second-order particle swarming model that describes the evolution of N N particles in R d \mathbb {R}^d under radial interactions. We propose a learning approach that models the latent radial interaction function as Gaussian processes, which can simultaneously fulfill two inference goals: one is the nonparametric inference of the interaction function with pointwise uncertainty quantification, and the other is the inference of unknown scalar parameters in the noncollective friction forces of the system. We formulate the learning problem as a statistical inverse learning problem and introduce an operator-theoretic framework that provides a detailed analysis of recoverability conditions, establishing that a coercivity condition is sufficient for recoverability. Given data collected from M M i.i. d trajectories with independent Gaussian observational noise, we provide a finite-sample analysis, showing that our posterior mean estimator converges in a Reproducing Kernel Hilbert Space norm, at an optimal rate in M M equal to the one in the classical 1-dimensional Kernel Ridge regression. As a byproduct, we show we can obtain a parametric learning rate in M M for the posterior marginal variance using L ∞ L^{\infty } norm and that the rate could also involve N N and L L (the number of observation time instances for each trajectory) depending on the condition number of the inverse problem. We provide numerical results on systems exhibiting different swarming behaviors, highlighting the effectiveness of our approach in the scarce, noisy trajectory data regime.
Design and stability analysis of networked control systems with random communication time delay using the modified MPC

This paper describes a novel control technique to deal with networked control systems with random communication time delay, which is known to highly degrade the control performance of the controlled system. This problem can be solved using a modified model predictive control, which uses the future control sequence to compensate for the forward communication time delay. Also, using a model predictor, the time delay in the backward channel can be compensated as well. Another key part of this paper is to analyse the stability of the networked control systems. The analytical criteria are obtained for both fixed and random communication time delays. The simulation results and practical experiments illustrate that the proposed controller design is realistic.
On curvature‐homogeneous spaces of type (1,3)

Curvature homogeneous spaces have been studied by many authors. In this paper, we introduce and study a natural modification of this class, namely so‐called curvature homogeneous spaces of type (1,3). We present a class of proper examples in every dimension and we prove a classification theorem in dimension 3 (for the generic case). We restrict ourselves to the Riemannian situation and to curvature homogeneity of order zero.
Density functional theory study of platinum oxides: From infinite crystals to nanoscopic particles

For over a century, platinum oxides find technologically relevant applications in various fields ranging from catalysis to electrochemistry and nanoelectronics. We have performed a density functional theory study of the PtO, ${\mathrm{Pt}}_{3}{\mathrm{O}}_{4}$, and $\mathrm{Pt}{\mathrm{O}}_{2}$ bulk oxide phases. In our calculations, PtO and ${\mathrm{Pt}}_{3}{\mathrm{O}}_{4}$ present metallic character at the simple generalized gradient approximation level. The application of Hubbard corrections to the Kohn-Sham Hamiltonian opens a small gap in the electronic band structure of PtO, but not of ${\mathrm{Pt}}_{3}{\mathrm{O}}_{4}$, in which metallic Pt-Pt bonds are revealed by a Bader analysis of the calculated electronic structure. These results, together with the noninteger oxidation number of the Pt ions, are indicative of metallicity of the ${\mathrm{Pt}}_{3}{\mathrm{O}}_{4}$ phase which may be consistent with the known metallic character of platinum bronzes. Moreover, we have calculated the relative thermodynamic stabilities of platinum oxide Wulff's particles and discussed the results in the context of catalysis. Finally, we have predicted that the formation of $\ensuremath{\alpha}\text{\ensuremath{-}}\mathrm{Pt}{\mathrm{O}}_{2}$ nanotubes could be energetically feasible. This result is of potential interest both for nanotechnological and catalytic applications and may explain the formation of curled $\ensuremath{\alpha}\text{\ensuremath{-}}\mathrm{Pt}{\mathrm{O}}_{2}$ sheets observed in high-resolution transmission electron microscopy images.
A computational scheme for linear and non‐linear composites with arbitrary phase contrast

A numerical method making use of fast Fourier transforms has been proposed in Moulinec and Suquet (1994, 1998) to investigate the effective properties of linear and non‐linear composites. This method is based on an iterative scheme the rate of convergence of which is proportional to the contrast between the phases. Composites with high contrast (typically above 104) or infinite contrast (those containing voids or rigid inclusions or highly non‐linear materials) cannot be handled by the method. This paper presents two modified schemes. The first one is an accelerated scheme for composites with high contrast which extends to elasticity a scheme initially proposed in Eyre and Milton (1999). Its rate of convergence varies as the square root of the contrast. The second scheme, adequate for composites with infinite contrast, is based on an augmented Lagrangian method. The resulting saddle‐point problem involves three steps. The first step consists of solving a linear elastic problem, using the fast Fourier transform method. In the second step, a non‐linear problem is solved at each individual point in the volume element. The third step consists of updating the Lagrange multiplier. Applications of this scheme to rigidly reinforced and to voided composites are shown. Copyright © 2001 John Wiley & Sons, Ltd.
Swing-up of Furuta Pendulum by Nonlinear Sliding Mode Control

: This paper presents a nonlinear sliding mode control and its applications to swing-up and stabilization of a Furuta pendulum. The nonlinear sliding mode is computed by the State Dependent Riccati Equation. The approach is based on the Lyapunov function and the stability is assured under the given condition. The validity of the proposed design method is studied through the simulation of swing-up / stabilization control.
Collaborative Web Search

Most of the existing metric learning methods are accomplished by exploiting pairwise constraints over the labeled data and frequently suffer from the insufficiency of training examples. To learn a robust distance metric from few labeled examples, prior knowledge from unlabeled examples as well as the metrics previously derived from auxiliary data sets can be useful. In this paper, we propose to leverage such auxiliary knowledge to assist distance metric learning, which is formulated following the regularized loss minimization principle. Two algorithms are derived on the basis of manifold regularization and log-determinant divergence regularization technique, respectively, which can simultaneously exploit label information (i.e., the pairwise constraints over labeled data), unlabeled examples, and the metrics derived from auxiliary data sets. The proposed methods directly manipulate the auxiliary metrics and require no raw examples from the auxiliary data sets, which make them efficient and flexible. We conduct extensive evaluations to compare our approaches with a number of competing approaches on face recognition task. The experimental results show that our approaches can derive reliable distance metrics from limited training examples and thus are superior in terms of accuracy and labeling efforts.
Effect of the time constant on the performance of a multichannel compression hearing aid

Previous research [E. W. Yund, H. J. Simon, and R. Efron, J. Rehab. Res. Dev. 24, 161–180 (1987)] demonstrated the effectiveness of an eight‐channel compression hearing aid for individuals with sensorineural hearing loss (SNHL) for speech discrimination in a background of speech‐band noise. In the present study, the averaging time window of the Robinson and Huntington [J. Acoust. Soc. Am. 54, 314 (1973)] compression was varied between 5 and 100 ms. Constant intensity, sinusoidally modulated, and square wave modulated speech‐band noise were used. Nonsense syllable discrimination of 15 subjects with SNHL showed no significant change with averaging time in constant intensity noise. Only the use of the square‐wave modulated noise revealed an effect of time window on discrimination, better discrimination with the two longer time windows (36.8 and 100 ms) as compared to the two shorter time windows (5 and 13.6 ms). These results indicate that a hearing‐impaired patient's success with such a multichannel compres.
Exact tests for 2×2 contingency tables

Abstract Fisher's exact test, difference in proportions, log odds ratio, Pearson's chi-squared, and likelihood ratio are compared as test statistics for testing independence of two dichotomous factors when the associated p values are computed by using the conditional distribution given the marginals. The statistics listed above that can be used for a one-sided alternative give identical p values. For a two-sided alternative, many of the above statistics lead to different p values. The p values are shown to differ only by which tables in the opposite tail from the observed table are considered more extreme than the observed table.
Rayleigh–Raman Depolarization of Laser Light Scattered by Gases

The polarization of the fine structure of the Rayleigh line for light scattered by simple gas molecules is examined. New and simple relations are reported between the depolarization factor of the total line (including rotational Raman lines) and the depolarization factor of the unshifted central component. A new high‐resolution apparatus for light scattering measurements in gases with photon‐counting electronics and a high‐power argon‐ion laser light source is described. New measurements of the depolarization factor of the total line are reported for H2, N2, O2, CO2, CO, and N2O. High‐resolution measurements of the depolarization factor of the central component are also reported for these gases and a critical comparison is made between experiment and classical light scattering theory. In the case of H2 a comparison with recent quantum mechanical calculations is also included.
Artifacts in X‐ray Dark‐Field Tomography

Grating‐based x‐ray imaging provides three principle kinds of contrast: absorption, phase, and dark‐field. Due to the availability of tomographic reconstruction algorithms for the dark‐field contrast, it is now possible to take advantage of quantitative scatter information. However, the published algorithm is based on several assumptions that might be violated in reality. We use numerical simulations in order to identify artifacts in the reconstructions, which is crucial for the interpretation of experimental data.
The discrete ordinate/pseudo-spectral method: review and application from a physicist's perspective

A discussion of the discrete ordinate method for solving differential equations is presented along with a number of examples that have application in various fields of physics. In particular, diffusion cooling, boundary layer meteorology and the diffusion of water in soils are studied. It is shown that the discrete ordinate method is considerably more accurate than finite difference methods of the same order. Results are presented for linear and nonlinear models, with a comprehensive analysis of the results and accuracies.
Stable dereverberation using microphone arrays for speaker verification

The impulse response of a reverberant environment, in general, is a nonminimum phase and cannot be inverted. But an exact inverse of the environment can be obtained by modeling the room as a multiple input–output (MINT) system [M. Miyoshi and Y. Kaneda ICASSP (1986)]. In this report, this model is applied to a microphone array and is used as a front‐end processor for a speaker verification system. The G matrix is inverted using row action projection (RAP), an iterative approach to solving a system of linear equations. Starting from an initial guess, the solution is repeatedly projected onto each hyperplane of the equation system until it converges. The method is stable, robust to noise, and converges to the pseudo‐inverse solution. In computer‐simulated experiments, the signal‐to‐reverberant‐noise ratio is found to improve with the number of microphones in the array. A speaker verification system using the array is evaluated at various signal‐to‐competing‐noise ratios (SCNR). Results suggest that verifica.
A Tunable Bandpass Filter with Constant Absolute Bandwidth

A novel tunable bandpass filter with constant absolute bandwidth is presented in this paper. Introducing a mixed electric and magnetic coupling structure and a new external coupling scheme, nearly constant absolute bandwidth is maintained across the tuning range. Theoretical analysis and design approach are demonstrated. The proposed filter is designed with a frequency coverage of 0.78–1.08 GHz and constant 3-dB bandwidth of 50 MHz over the tuning range. The experimental results show good performance of the filter and validate the design concept.
Analysis of the transition region between a uniform plasma and its confining magnetic field: II

The case of one‐dimensional geometry for the transition region separating a uniform plasma from its confining magnetic field is considered. The magnetic‐field profile within the boundary layer is determined by the current distribution, i.e., by the paths of the ions and electrons. The paths of these particles, on the other hand, are determined by the fields in which they move. An exact, self‐consistent solution of Maxwell's equations and the equations of motion of the particles is obtained. A detailed analysis is made for a hydrogen plasma. These results are then compared with those of a plasma whose positive constituent is the proton and whose negative constituent has a mass which approaches zero and a speed which approaches infinity in such a way that the energy remains finite. The transition layer thickness for these two plasmas agree to one part in 106. It is shown that this latter case is equivalent to treating the electrons of the hydrogen plasma in the guiding‐center approximation.
An Asymmetric Outflow from the Herbig Ae Star HD 163296

We present an observational picture of the HH 409 bipolar outflow including the detection of six previously unreported Herbig-Haro knots from the Herbig Ae star HD 163296. This study combines seven years of data from ground-based Fabry-Pérot and HST coronagraphic imagery, as well as HST long-slit spectral imagery. The redshifted counterjet includes a chain of six Herbig-Haro knots spanning >27'' to the northeast (P.A. ≈ 42°) of the source and has been active for >80 yr. The brightest knot in the counterjet is HH 409 C, a low-excitation bow shock with a shock velocity Vs ~ 50 km s-1 and total space motion Vjet ≈ 260 km s-1. The presence of additional knots in the counterjet beyond the bow shock may indicate precession of the jet axis. The blueshifted jet includes two closely spaced knots within 10'' and a distant bow shock (≈21'') southwest (P.A. ≈ 223°) of the source. The brightest knot in the jet is HH 409 A, a higher excitation more bullet-like shock with Vs ~ 90 km s-1 and Vjet ≈ 360 km s-1. The average opening angles for both the jet and counterjet are similar, αa ~ 2°, and consistent with opening angles of lower mass T Tauri stars. The mass-loss rates in both lobes of the flow, despite the asymmetry of the knots, are also comparable, out ~ 1.0 × 10-8 M☉ yr-1. This suggests that variations in the mass outflow rate are not more than a factor of ~2.
EGRET high-energy gamma-ray pulsar studies. 1: Young spin-powered pulsars

As part of its ongoing survey of the high-energy gamma-ray sky, the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory has searched for emission from spin-powered pulsars, five of which have now been detected in the energy range 30 MeV less than or = E less than or = 20 GeV. A systematic study of the all-sky survey has found no additional pulsed gamma-ray sources. The pulsar detections, coupled with the upper limits on pulsed gamma radiation from other radio pulsars, indicate that the simplest models of gamma-ray pulsars are incomplete.
Structural Equation Modeling: Mixture Models

This article discusses a modeling framework that links two well-known statistical methods: structural equation modeling (SEM) and latent class or finite mixture modeling. Mixture SEM can either be viewed as a refinement of multivariate normal (MVN) mixtures, where the within-class covariance matrices are smoothed according to a postulated SEM structure, or as a form of multiple group SEM, in which the group variable is unobserved. After introducing standard MVN mixtures, it is shown how the SEM framework can be used to restrict the class-specific means and covariances. Furthermore, parameter estimation, model testing, and software is discussed, and an empirical example is provided. Keywords: mixtures of multivariate normal distributions; model-based clustering; mixture factor analysis; latent class analysis; latent profile analysis; unobserved heterogeneity; EM algorithm; covariance structures
Metagenome-Assembled Genome of a Cyclobacteriaceae Bacterium, HetDA_MAG_MS6, Isolated from a Trichodesmium Consortium from Station ALOHA

Here, we describe the metagenome-assembled genome (MAG) HetDA_MAG_MS6. HetDA_MAG_MS6 was obtained from an enrichment of the heterocystous diazotroph HetDA, which was isolated near Station ALOHA. The MAG was placed in the Cyclobacteriaceae family and is predicted to be a chemoorganoheterotroph with the potential for ammonia uptake, phosphonate transport, and sulfolipid biosynthesis. ABSTRACT Here, we describe the metagenome-assembled genome (MAG) HetDA_MAG_MS6. HetDA_MAG_MS6 was obtained from an enrichment of the heterocystous diazotroph HetDA, which was isolated near Station ALOHA. The MAG was placed in the Cyclobacteriaceae family and is predicted to be a chemoorganoheterotroph with the potential for ammonia uptake, phosphonate transport, and sulfolipid biosynthesis.