Miracle-dz/UniFAR-FTUs huggingface dataset:
A NOVEL EMISSION SPECTRUM FROM A RELATIVISTIC ELECTRON MOVING IN A RANDOM MAGNETIC FIELD

We numerically calculate the radiation spectrum from relativistic electrons moving in small-scale turbulent magnetic fields expected in high-energy astrophysical sources. Such a radiation spectrum is characterized by the strength parameter a = λBe|B|/mc2, where λB is the length scale of the turbulent field. When a is much larger than the Lorentz factor of a radiating electron γ, synchrotron radiation is realized, while a ≪ 1 corresponds to the so-called jitter radiation regime. Because for 1 < a < γ we cannot use either approximations, we should have recourse to the Lienard–Wiechert potential to evaluate the radiation spectrum, which is performed in this Letter. We generate random magnetic fields assuming Kolmogorov turbulence, inject monoenergetic electrons, solve the equation of motion, and calculate the radiation spectrum. We perform numerical calculations for several values of a with γ = 10. We obtain various types of spectra ranging between jitter radiation and synchrotron radiation. For a ∼ 7, the spectrum takes a novel shape which had not been noticed up to now. It is like a synchrotron spectrum in the middle energy region, but in the low frequency region it is a broken power law and in the high frequency region an extra power-law component appears beyond the synchrotron cutoff. We give a physical explanation of these features.
Derivative expansion of the electromagnetic Casimir energy for two thin mirrors

We extend our previous work on a derivative expansion for the Casimir energy, to the case of the electromagnetic field coupled to two thin, imperfect mirrors. The latter are described by means of vacuum polarization tensors localized on the mirrors. We apply the results so obtained to compute the first correction to the proximity force approximation to the static Casimir effect.
OGLE-III MICROLENSING EVENTS AND THE STRUCTURE OF THE GALACTIC BULGE

We present and study the largest and most comprehensive catalog of microlensing events ever constructed. The sample of standard microlensing events comprises 3718 unique events from 2001–2009 with 1409 events that had not been detected before in real-time by the Early Warning System of the Optical Gravitational Lensing Experiment. The search pipeline uses machine learning algorithms to help find rare phenomena among 150 million objects and to derive the detection efficiency. Applications of the catalog can be numerous, from analyzing individual events to large statistical studies of the Galactic mass, kinematics distributions, and planetary abundances. We derive maps of the mean Einstein ring crossing time of events spanning 31 deg2 toward the Galactic center and compare the observed distributions with the most recent models. We find good agreement within the observed region and we see the signature of the tilt of the bar in the microlensing data. However, the asymmetry of the mean timescales seems to rise more steeply than predicted, indicating either a somewhat different orientation of the bar or a larger bar width. The map of events with sources in the Galactic bulge shows a dependence of the mean timescale on the Galactic latitude, signaling an increasing contribution from disk lenses closer to the plane relative to the height of the disk. Our data present a perfect set for comparing and enhancing new models of the central parts of the Milky Way and creating a three-dimensional picture of the Galaxy.
NIP ω$\omega$ ‐categorical structures: The rank 1 case

We classify primitive, rank 1, ω$\omega$ ‐categorical structures having polynomially many types over finite sets. We show that there are only finitely many such structures with a fixed number of 4‐types and that they are built out of finitely many linear or circular orders interacting in a restricted number of ways. As an example of application, we deduce the classification of primitive structures homogeneous in a language consisting of n$n$ linear orders as well as all reducts of such structures.
STEADY X-RAY SYNCHROTRON EMISSION IN THE NORTHEASTERN LIMB OF SN 1006

We investigate time variations and detailed spatial structures of X-ray synchrotron emission in the northeastern limb of SN 1006, using two Chandra observations taken in 2000 and 2008. We extract spectra from a number of small (∼10″) regions. After taking account of proper motion and isolating the synchrotron from the thermal emission, we study time variations in the synchrotron emission in the small regions. We find that there are no regions showing strong flux variations. Our analysis shows an apparent flux decline in the overall synchrotron flux of ∼4% at high energies, but we suspect that this is mostly a calibration effect, and that flux is actually constant to ∼1%. This is much less than the variation found in other remnants where it was used to infer magnetic-field strengths up to 1 mG. We attribute the lack of variability to the smoothness of the synchrotron morphology, in contrast to the small-scale knots found to be variable in other remnants. The smoothness is to be expected for a Type Ia remnant encountering uniform material. Finally, we find a spatial correlation between the flux and the cutoff frequency in synchrotron emission. The simplest interpretation is that the cutoff frequency depends on the magnetic-field strength. This would require that the maximum energy of accelerated electrons is not limited by synchrotron losses, but by some other effect. Alternatively, the rate of particle injection and acceleration may vary due to some effect not yet accounted for, such as a dependence on shock obliquity.
Superfluid transport dynamics in a capacitive atomtronic circuit

We simulate transport in an atomtronic circuit of a Bose-Einstein condensate that flows from a source region into a drain through a gate channel. The time-dependent Gross-Pitaevskii equation (GPE) solution matches the data of a recent experiment. The atomtronic circuit is found to be similar to a variable-resistance RLC circuit, which is critically damped at early times and shows LC oscillations later. The GPE also predicts atom loss from the drain. Studies of the dependence of condensate transport upon gate parameters suggest the utility of the GPE for investigation of atomtronic circuits.
Observation of squeeze-twist coupling in a chiral three-dimensional isotropic lattice in a chiral

A chiral 3D lattice was designed, made by 3D printing, and studied experimentally. The lattice exhibited squeeze-twist coupling and a Poisson’s ratio near zero. Squeeze-twist coupling does not occur in classical elasticity which makes no provision for chirality. By contrast, chiral eﬀects are allowed in Cosserat elasticity. An experimental squeeze-twist coupling strain ratio on the order of unity and a Poisson’s ratio near zero are in reasonable agreement with prior ﬁnite element analysis of a lattice with similar structure, for which negative Poisson’s ratio is anticipated for a suﬃcient number of cells.
Tightly Coupled 3D Lidar Inertial Odometry and Mapping

Ego-motion estimation is a fundamental requirement for most mobile robotic applications. By sensor fusion, we can compensate the deficiencies of stand-alone sensors and provide more reliable estimations. We introduce a tightly coupled lidar-IMU fusion method in this paper. By jointly minimizing the cost derived from lidar and IMU measurements, the lidarIMU odometry (LIO) can perform well with considerable drifts after long-term experiment, even in challenging cases where the lidar measurement can be degraded. Besides, to obtain more reliable estimations of the lidar poses, a rotation-constrained refinement algorithm (LIO-mapping) is proposed to further align the lidar poses with the global map. The experiment results demonstrate that the proposed method can estimate the poses of the sensor pair at the IMU update rate with high precision, even under fast motion conditions or with insufficient features.
Non-linear resonance in relativistic preheating

Inflation in the early Universe can be followed by a brief period of preheating, resulting in rapid and non-equilibrium particle production through the dynamics of parametric resonance. However, the parametric resonance effect is very sensitive to the linearity of the reheating sector. Additional self-interactions in the reheating sector, such as non-canonical kinetic terms like the DBI Lagrangian, may enhance or frustrate the parametric resonance effect of preheating. In the case of a DBI reheating sector, preheating is described by parametric resonance of a damped relativistic harmonic oscillator. In this paper, we illustrate how the non-linear terms in the relativistic oscillator shut down the parametric resonance effect. This limits the effectiveness of preheating when there are non-linear self-interactions.
Rationality of capped descendent vertex in $K$-theory

In this paper we analyze the fundamental solution of the \textit{quantum difference equation} (qde) for the moduli space of instantons on two-dimensional projective space. The qde is a $K$-theoretic generalization of the quantum differential equation in quantum cohomology. As in the quantum cohomology case, the fundamental solution of qde provides the capping operator in $K$-theory (the rubber part of the capped vertex). We study the dependence of the capping operator on the equivariant parameters $a_i$ of the torus acting on the instanton moduli space by changing the framing. We prove that the capping operator factorizes at $a_i\to 0$. The rationality of the $K$-theoretic 1-leg capped descendent vertex follows from factorization of the capping operator as a simple corollary.
ORIGIN OF CHEMICAL AND DYNAMICAL PROPERTIES OF THE GALACTIC THICK DISK

We adopt a scenario in which the Galactic thick disk was formed by minor merging between the first generation of the Galactic thin disk (FGTD) and a dwarf galaxy about ∼9 Gyr ago and thereby investigate chemical and dynamical properties of the Galactic thick disk. In this scenario, the dynamical properties of the thick disk have long been influenced both by the mass growth of the second generation of the Galactic thin disk (i.e., the present thin disk) and by its non-axisymmetric structures. On the other hand, the early star formation history and chemical evolution of the thin disk was influenced by the remaining gas of the thick disk. Based on N-body simulations and chemical evolution models, we investigate the radial metallicity gradient, structural and kinematical properties, and detailed chemical abundance patterns of the thick disk. Our numerical simulations show that the ancient minor merger event can significantly flatten the original radial metallicity gradient of the FGTD, in particular, in the outer part, and also can be responsible for migration of inner metal-rich stars into the outer part (R > 10 kpc). The simulations show that the central region of the thick disk can develop a bar due to dynamical effects of a separate bar in the thin disk. Whether or not rotational velocities (Vϕ) can correlate with metallicities ([Fe/H]) for the simulated thick disks depends on the initial metallicity gradients of the FGTDs. The simulated orbital eccentricity distributions in the thick disk for models with higher mass ratios (∼0.2) and lower orbital eccentricities (∼0.5) of minor mergers are in good agreement with the corresponding observations. The simulated Vϕ–|z| relation of the thick disk in models with low orbital inclination angles of mergers are also in good agreement with the latest observational results. The vertical metallicity gradient of the simulated thick disk is rather flat or very weakly negative in the solar neighborhood. Our Galactic chemical evolution models show that if we choose two distinctive timescales for star formation in the thin and thick disks, then the models can explain both the observed metallicity distribution functions and correlations between [Mg/Fe] and [Fe/H] for the two disks in a self-consistent manner. We discuss how the early star formation history and chemical evolution of the Galactic thin disk can be influenced by the pre-existing thick disk.
Spiral-induced velocity and metallicity patterns in a cosmological zoom simulation of a Milky Way-sized galaxy

We use a high resolution cosmological zoom simulation of a Milky Way-sized halo to study the observable features in velocity and metallicity space associated with the dynamical influence of spiral arms. For the first time, we demonstrate that spiral arms, that form in a disc in a fully cosmological environment with realistic galaxy formation physics, drive large-scale systematic streaming motions. In particular, on the trailing edge of the spiral arms the peculiar galacto-centric radial and azimuthal velocity field is directed radially outward and azimuthally backward, whereas it is radially inward and azimuthally forward on the leading edge. Owing to the negative radial metallicity gradient, this systematic motion drives, at a given radius, an azimuthal variation in the residual metallicity that is characterised by a metal rich trailing edge and a metal poor leading edge. We show that these signatures are theoretically observable in external galaxies with Integral Field Unit instruments such as VLT/MUSE, and if detected, would provide evidence for large-scale systematic radial migration driven by spiral arms.
BOOSTED TIDAL DISRUPTION BY MASSIVE BLACK HOLE BINARIES DURING GALAXY MERGERS FROM THE VIEW OF N-BODY SIMULATION

Supermassive black hole binaries (SMBHBs) are productions of the hierarchical galaxy formation model. There are many close connections between a central SMBH and its host galaxy because the former plays very important roles on galaxy formation and evolution. For this reason, the evolution of SMBHBs in merging galaxies is a fundamental challenge. Since there are many discussions about SMBHB evolution in a gas-rich environment, we focus on the quiescent galaxy, using tidal disruption (TD) as a diagnostic tool. Our study is based on a series of numerical, large particle number, direct N-body simulations for dry major mergers. According to the simulation results, the evolution can be divided into three phases. In phase I, the TD rate for two well separated SMBHs in a merging system is similar to that for a single SMBH in an isolated galaxy. After two SMBHs approach close enough to form a bound binary in phase II, the disruption rate can be enhanced by ∼2 orders of magnitude within a short time. This “boosted” disruption stage finishes after the SMBHB evolves to a compact binary system in phase III, corresponding to a reduction in disruption rate back to a level of a few times higher than in phase I. We also discuss how to correctly extrapolate our N-body simulation results to reality, and the implications of our results to observations.
Evolution of the coupling constant in SU(2) lattice gauge theory with two adjoint fermions

We measure the evolution of the coupling constant using the Schroedinger functional method in the lattice formulation of SU(2) gauge theory with two massless Dirac fermions in the adjoint representation. We observe strong evidence for an infrared fixed point, where the theory becomes conformal. We measure the {beta} function and the coupling constant as a function of the energy sca0008.
THE NEXT GENERATION VIRGO CLUSTER SURVEY XVI: THE ANGULAR MOMENTUM OF DWARF EARLY-TYPE GALAXIES FROM GLOBULAR CLUSTER SATELLITES

We analyze the kinematics of six Virgo cluster dwarf early-type galaxies (dEs) from their globular cluster (GC) systems. We present new Keck/DEIMOS spectroscopy for three of them and re-analyze the data found in the literature for the remaining three. We use two independent methods to estimate the rotation amplitude (Vrot) and velocity dispersion (σGC) of the GC systems and evaluate their statistical significance by simulating non-rotating GC systems with the same number of GC satellites and velocity uncertainties. Our measured kinematics agree with the published values for the three galaxies from the literature and, in all cases, some rotation is measured. However, our simulations show that the null hypothesis of being non-rotating GC systems cannot be ruled out. In the case of VCC 1861, the measured Vrot and the simulations indicate that it is not rotating. In the case of VCC 1528, the null hypothesis can be marginally ruled out, and thus it might be rotating although further confirmation is needed. In our analysis, we find that, in general, the measured Vrot tends to be overestimated and the measured σGC tends to be underestimated by amounts that depend on the intrinsic Vrot/σGC, the number of observed GCs (NGC), and the velocity uncertainties. The bias is negligible when NGC ≳ 20. In those cases where a large NGC is not available, it is imperative to obtain data with small velocity uncertainties. For instance, errors of ≤2 km s−1 lead to Vrot < 10 km s−1 for a system that is intrinsically not rotating.
Angular momentum transfer to a Milky Way disc at high redshift

An Adaptive Mesh Refinement cosmological resimulation is analyzed in order to test whether filamentary flows of cold gas are responsible for the build-up of angular momentum within a Milky Way like disk at z>=3. A set of algorithms is presented that takes advantage of the high spatial resolution of the simulation (12 pc) to identify: (i) the central gas disk and its plane of orientation; (ii) the complex individual filament trajectories that connect to the disk, and; (iii) the infalling satellites. The results show that two filaments at z>5.5, which later merge to form a single filament at z<4, drive the angular momentum and mass budget of the disk throughout its evolution, whereas luminous satellite mergers make negligible fractional contributions. Combined with the ubiquitous presence of such filaments in all large-scale cosmological simulations that include hydrodynamics, these findings provide strong quantitative evidence that the growth of thin disks in haloes with masses below 10^{12} M_{sun}, which host the vast majority of galaxies, is supported via inflowing streams of cold gas at intermediate and high redshifts.
Terrestrial ages of seven meteorite strewn fields and two single unpaired meteorites from the Sultanate of Oman determined using 14C and 10Be

Through the investigation of terrestrial ages of meteorites from Oman, we aim to better understand the time scales of meteorite accumulation and erosion in Oman and the meteorite flux in the past. Here, we present 14C and 14C‐10Be terrestrial ages of seven ordinary chondrite strewn fields and two unpaired single meteorites from the Sultanate of Oman. After critical evaluation of multiple data for each strewn field, we propose “best estimate terrestrial ages,” typically based on 14C/10Be. For objects for which complex irradiation histories are known or suspected, terrestrial ages were calculated solely using 14C. The best estimate strewn field ages range from 8.1 ± 3.0 ka (SaU 001) to 35.2 ± 5.1 ka (Dho 005). Including two previously dated strewn fields, the mean and median age of nine Oman strewn fields is 15.9 ± 12.3 and 13.6 ka, respectively. The new data show a general good agreement with data previously obtained in a different laboratory, and we observe a similar general correlation between strewn field ages and mean weathering grade as in previous work based on individual meteorites. Weathering degree W4 is reached for dated samples after 20–35 ka. While the age statistics of strewn fields does not show the previously observed lack of young events, the low abundance of young (0–5 ka) individual meteorites as compared with older (~20 ka) meteorites is confirmed by our data and remains unexplained.
Chemical history of isolated dwarf galaxies of the Local Group – I. dSphs: Cetus and Tucana

For the first time, we obtain chemical evolution models (CEMs) for Tucana and Cetus, two isolated dwarf spheroidal galaxies (dSphs) of the Local Group. The CEMs have been built from the star formation histories (SFHs) and the metallicity histories, both obtained independently by the LCID project from deep color-magnitude dia- grams. Based on our models, we find that the chemical histories were complex and can be divided into different epochs and scenarios. In particular, during 75 percent of the SFH, the galaxies behaved as closed boxes and, during the remaining 25 percent, either received a lot of primordial gas by accretion or they lost metals through metal-rich winds. In order to discriminate between these two scenarios, abundances ratios in old stars are needed. At t approximately 4.5 Gyr, the galaxies lost most of their gas due to a short-strong, well-mixed wind. We obtain very similar CEMs for both galaxies, although Cetus is twice as massive as Tucana. We conclude that the star formation in both galaxies began with only 1.5 percent of the baryonic mass fraction predicted by lambda CDM.
Generating Multiple Hypotheses for 3D Human Pose Estimation With Mixture Density Network

3D human pose estimation from a monocular image or 2D joints is an ill-posed problem because of depth ambiguity and occluded joints. We argue that 3D human pose estimation from a monocular input is an inverse problem where multiple feasible solutions can exist. In this paper, we propose a novel approach to generate multiple feasible hypotheses of the 3D pose from 2D joints. In contrast to existing deep learning approaches which minimize a mean square error based on an unimodal Gaussian distribution, our method is able to generate multiple feasible hypotheses of 3D pose based on a multimodal mixture density networks. Our experiments show that the 3D poses estimated by our approach from an input of 2D joints are consistent in 2D reprojections, which supports our argument that multiple solutions exist for the 2D-to-3D inverse problem. Furthermore, we show state-of-the-art performance on the Human3.6M dataset in both best hypothesis and multi-view settings, and we demonstrate the generalization capacity of our model by testing on the MPII and MPI-INF-3DHP datasets. Our code is available at the project website.
Understanding experiences of disclosing and receiving disclosures of nonsuicidal self-injury amongst peers in university: A qualitative investigation

ABSTRACT Nonsuicidal self-injury (NSSI) is a frequently occurring mental health concern among emerging adults in university, but one that is often concealed. Given that the disclosure of NSSI can provide opportunities to receive support, promoting positive disclosure experiences for students is important. However, the experiences of disclosing for both disclosers and recipients are not well understood. In the present study, we examined experiences leading up to, during, and following disclosures from students with lived experience giving and/or receiving a peer disclosure of NSSI. Semi-structured interviews were conducted with 20 undergraduate students (M age = 19.95, 80% female), and reflexive thematic analysis was used. Four shared themes were identified : 1) The choice to disclose is a social cost-benefit analysis, in which context and past experiences matter, 2) Individuals seek emotional and practical support from their peers via disclosure, 3) Supportive responding constitutes care, empathy, and non-judgment, and 4) Disclosure can lead to awareness, change, and growth. One theme was unique to recipients: 5) Disclosure can be an overwhelming process, and many recipients feel ill-equipped to respond. Findings can be used to inform mental health literacy efforts for students on university campuses.