ShantanuT01/DACTYL-Pretraining huggingface dataset:
The parameters of the Galactic spiral wave are re-determined using a modified periodogram (spectral) analysis of the galactocentric radial velocities of 58 masers with known trigonometric parallaxes, proper motions, and line-of-site velocities. The masers span a wide range of galactocentric distances, $3<$R$<14$ kpc, which, combined with a large scatter of position angles $\theta$ of these objects in the Galactic plane XY, required an accurate account of logarithmic dependence of spiral-wave perturbations on both galactocentric distance and position angle. A periodic signal was detected corresponding to the spiral density wave with the wavelength $\lambda=2.4 \pm 0.4$ kpc, peak velocity of wave perturbations $f_R=7.5 \pm 1.5$ km s$^{-1}$, the phase of the Sun in the density wave $\chi_\odot=-160 \pm 15^\circ$, and the pitch angle of $-5.5 \pm 1^\circ$.
INTEGRAL has made a very significant contribution to our understanding of the physics of AGN. We illustrate this progress by looking at the considerations that were made at the time of the selection of the INTEGRAL mission and discussing some observations and results obtained in the intervening time.   It is seen that while a number of results pertaining to the variability of AGN have been obtained, the potential of the INTEGRAL data in short timescale variability domain is still largely under exploited. The characteristic variability timescale of AGN, and X-ray binaries, can be understood in the frame of the cascade of shocks model and more generally depends solely on the Compton cooling properties of a hot electron plasma located at a distance proportional to the mass of the object from a soft photon source.   Although INTEGRAL is not a focusing instrument, it is possible to resolve a small but significant fraction of the diffuse extragalactic background at energies higher than 10\,keV.
Let $K$ be the quotient field of a discrete valuation ring $R$ with residue characteristic $\not=2$, and let $C$ be a hyperelliptic curve over $K$. We assume that all geometric branch points of the double covering $C\twoheadrightarrow{\mathbb P}^1_K$ are rational and mark both $C$ and ${\mathbb P}^1_K$ with these branch points. After possibly replacing $R$ by a ramified extension of degree $2$, we give a direct construction for the stable model of $C$ as a marked curve over $R$. We deduce that the closed fiber of this stable model is determined completely by the closed fiber of the stable model of the marked ${\mathbb P}^1_K$. In particular, the dual graph and other information for the former can be read off directly from the corresponding information for the latter.
We calculate the production of real photons originating from the photoproduction in relativistic $pp$ collisions. The Weizs$\ddot{\mathrm{a}}$cker-Williams approximation in the photoproduction is considered. Numerical results agree with the experimental data from Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC). We find that the modification of the photoproduction is more prominent in large transverse momentum region.
Multi-person human pose estimation and tracking in the wild is important and challenging. For training a powerful model, large-scale training data are crucial. While there are several datasets for human pose estimation, the best practice for training on multi-dataset has not been investigated. In this paper, we present a simple network called Multi-Domain Pose Network (MDPN) to address this problem. By treating the task as multi-domain learning, our methods can learn a better representation for pose prediction. Together with prediction heads fine-tuning and multi-branch combination, it shows significant improvement over baselines and achieves the best performance on PoseTrack ECCV 2018 Challenge without additional datasets other than MPII and COCO.
We present the results of the reverberation monitoring aimed at MgII broad line and FeII pseudocontinuum for the luminous quasar CTS C30.10 (z = 0.90052) with the Southern African Large Telescope covering the years 2012-2021. We aimed at disentangling the MgII and UV FeII variability and the first measurement of UV FeII time delay for a distant quasar. We used several methods for time-delay measurements and determined both FeII and MgII time delays as well as performed a wavelength-resolved time delay study for a combination of MgII and FeII in the 2700 - 2900 \AA restframe wavelength range. We obtain the time delay for MgII of $275.5^{+12.4}_{-19.5}$ days in the rest frame, while for FeII we have two possible solutions of $270.0^{+13.8}_{-25.3}$ days and $180.3^{+26.6}_{-30.0}$ in the rest frame. Combining this result with the old measurement of FeII UV time delay for NGC 5548 we discuss for the first time the radius-luminosity relation for UV FeII with the slope consistent with $0.5$ within uncertainties. Since FeII time delay has a shorter time-delay component but lines are narrower than MgII, we propose that the line delay measurement is biased towards the BLR part facing the observer, with the bulk of the Fe II emission may arise from the more distant BLR region, one that is shielded from the observer.
The unconditional entanglement swapping for continuous variables is experimentally demonstrated. Two initial entangled states are produced from two nondegenerate optical parametric amplifiers operating at deamplification. Through implementing the direct measurement of Bell-state between two optical beams from each amplifier the remaining two optical beams, which have never directly interacted with each other, are entangled. The quantum correlation degrees of 1.23dB and 1.12dB below the shot noise limit for the amplitude and phase quadratures resulting from the entanglement swapping are straightly measured.
Within the framework of covariant confined quark model, we compute the transition form factors of $D$ and $D_s$ mesons decaying to light scalar mesons $f_0(980)$ and $a_0(980)$. The transition form factors are then utilized to compute the semileptonic branching fractions. We study the channels namely, $D_{(s)}^+ \to f_0(980) \ell^+ \nu_\ell$ and $D \to a_0(980) \ell^+ \nu_\ell$ for $\ell = e$ and $\mu$. For computation of semileptonic branching fractions, we consider the $a_0(980)$ meson to be the conventional quark-antiquark structure and the $f_0(980)$ meson as the admixture of $s\bar{s}$ and light quark-antiquark pairs. Our findings are found to support the recent BESIII data.
The energy radiated during the scattering of SU(3) monopoles is estimated as a function of their asymptotic velocity v. In a typical scattering process the total energy radiated is of order v^3 as opposed to v^5 for SU(2) monopoles. For charge (1,1) monopoles the dipole radiation produced is estimated for all geodesics on the moduli space. For charge (2,1) monopoles the dipole radiation is estimated for the axially symmetric geodesic. The power radiated appears to diverge in the massless limit. The implications of this for the case of non-Abelian unbroken symmetry are discussed.
The prospect of mini black holes, either primordial or in planned experiments at the Large Hadron Collider, interacting with the earth motivate us to examine how they may be detected and the scope of their impact on the earth. We propose that the more massive of these objects may gravitationally bind matter without significant absorption. Since the wave functions of gravitationally bound atoms orbiting a black hole are analogous to those of electrons around a nucleus, we call such an object the Gravitationally Equivalent of an Atom (GEA). Mini black holes are expected to lose mass through quantum evaporation, which has become well accepted on purely theoretical grounds. Since all attempts to directly observe x-rays from an evaporating black hole have failed, we examine the possibility of the inverse test: search for extant mini black holes by looking for emissions from matter bound in a GEA. If quantum evaporation does not occur, then miniature black holes left over from the early universe may be stable, contribute to dark matter, and in principle be detectable through emissions associated with the bound matter. We show that small black holes-with masses below \sim10^12 kg-can bind matter without readily absorbing it into the black hole but the emissions are too weak to be detected from earth.
A sequence of real numbers (x_n) is Benford if the significands, i.e. the fraction parts in the floating-point representation of (x_n) are distributed logarithmically. Similarly, a discrete-time irreducible and aperiodic finite-state Markov chain with probability transition matrix P and limiting matrix P* is Benford if every component of both sequences of matrices (P^n - P*) and (P^{n+1}-P^n) is Benford or eventually zero. Using recent tools that established Benford behavior both for Newton's method and for finite-dimensional linear maps, via the classical theories of uniform distribution modulo 1 and Perron-Frobenius, this paper derives a simple sufficient condition (nonresonant) guaranteeing that P, or the Markov chain associated with it, is Benford. This result in turn is used to show that almost all Markov chains are Benford, in the sense that if the transition probabilities are chosen independently and continuously, then the resulting Markov chain is Benford with probability one. Concrete examples illustrate the various cases that arise, and the theory is complemented with several simulations and potential applications.
In this paper, we study various aspects of the equilibrium thermodynamic state space geometry of AdS black holes. We first examine the Reissner-Nordstrom-AdS (RN-AdS) and the Kerr-AdS black holes. In this context, the state space scalar curvature of these black holes is analysed in various regions of their thermodynamic parameter space. This provides important new insights into the structure and significance of the scalar curvature. We further investigate critical phenomena, and the behaviour of the scalar curvature near criticality, for KN-AdS black holes in two mixed ensembles, introduced and elucidated in our earlier work arXiv:1002.2538 [hep-th]. The critical exponents are identical to those in the RN-AdS and Kerr-AdS cases in the canonical ensemble. This suggests an universality in the scaling behaviour near critical points of AdS black holes. Our results further highlight qualitative differences in the thermodynamic state space geometry for electric charge and angular momentum fluctuations of these.
Twin-Field quantum key distribution (TF-QKD) and its variants, e.g. Phase-Matching QKD, Sending-or-not-sending QKD, and No Phase Post-Selection TFQKD promise high key rates at long distance to beat the rate distance limit without a repeater. The security proof of these protocols are based on decoy-state method, which is usually performed by actively modulating a variable optical attenuator together with a random number generator in practical experiments, however, active-decoy schemes like this may lead to side channel and could open a security loophole. To enhance the source security of TF-QKD, in this paper, we propose passive-decoy based TF-QKD, in which we combine TF-QKD with the passive-decoy method. And we present a simulation comparing the key generation rate with that in active-decoy, the result shows our scheme performs as good as active decoy TF-QKD, and our scheme could reach satisfactory secret key rates with just a few photon detectors. This shows our work is meaningful in practice.
We have analyzed the galaxy number density and luminosity density profiles of rich clusters of galaxies from redshifts z=0 to z=0.5. We show that the luminosity profile computed with bright galaxies is significantly cusped in the center of the clusters, whatever the redshift. This is in agreement with the dark matter profiles predicted by numerical simulations. The galaxy number density profile for the bright galaxies is fitted equally well with a core model or a cusped model. In contrast, the luminosity and the galaxy number density profiles of the fainter galaxies are significantly better fitted by a core rather than a cusp model. We did not detect any statistically significant different fits when applied to data in range from z=0 to z=0.5. The difference in profile between faint and bright galaxies may be due to the rapid (relative to the age of the universe at z=0 versus z=0.5) destruction of the faint galaxies by tidal forces and merging events in the denser central regions of the clusters. This process could erase the cusp by turning faint galaxies into diffuse light. In this case, the galaxies (with a cusp visible in the bright galaxy number density and mainly in luminosity profiles) would trace the total mass distribution.
Umbral dots (UDs) are transient, bright features observed in the umbral region of a sunspot. We study the physical properties of UDs observed in sunspots of different sizes. The aim of our study is to relate the physical properties of umbral dots with the large-scale properties of sunspots. For this purpose, we analyze high-resolution G-band images of 42 sunspots observed by {\em Hinode}/SOT, located close to disk center. The images were corrected for instrumental stray-light and restored with the modeled PSF. An automated multi-level tracking algorithm was employed to identify the UDs located in selected G-band images. Furthermore, we employed HMI/SDO, limb-darkening corrected, full disk continuum images to estimate the sunspot phase and epoch for the selected sunspots. The number of UDs identified in different umbrae exhibits a linear relation with the umbral size. The observed filling factor ranges from 3\% to 7\% and increases with the mean umbral intensity. Moreover, the filling factor shows a decreasing trend with the umbral size. We also found that the observed mean and maximum intensities of UDs are correlated with the mean umbral intensity. However, we do not find any significant relationship between the mean (and maximum) intensity and effective diameter of umbral dots with the sunspot area, epoch, and decay rate. We suggest that this lack of relation could either be due to the distinct transition of spatial scales associated with overturning convection in the umbra or the shallow depth associated with umbral dots, or both the above.
Several recent papers construct auxiliary polynomials to bound the Weil height of certain classes of algebraic numbers from below. Following these techniques, the author gave a general method for introducing auxiliary polynomials to problems involving the Weil height. The height appears as a solution to a certain extremal problem involving polynomials. We further generalize the above techniques to acquire both the projective height and the height on subspaces in the same way. We further obtain lower bounds on the heights of points on some subvarieties of $\mathbb P^{N-1}(\overline{\mathbb Q})$.
The initial-value problem for a particular bidirectional Whitham system modelling surface water waves is under consideration. This system was recently introduced in [4]. It is numerically shown to be stable and a good approximation to the incompressible Euler equations. Here we prove local in time well-posedness. Our proof relies on an energy method and a compactness argument.
An SO(3) picture of the generalized Grover's quantum searching algorithm,with arbitrary unitary transformation and with arbitrary phase rotations, is constructed. In this picture, any quantum search operation is a rotation in a 3 dimensional space. Exact formulas for the rotation angle and rotational axis are given. The probability of finding the marked state is just $(z+1)/2$, where z is the z-component of the state vector. Exact formulas for this probability is easily obtained. The phase matching requirement and the failure of algorithm when phase mismatches are clearly explained.
We investigate the evolution of phase transition of the classical fully compact dimer model on the bipartite square lattice with second nearest bonds at finite temperatures. We use the numeric Monte Carlo method with the directed-loop algorithm to simulate the model. Our results show that the order of the phase transition depends on the fugacity of the second nearest bonds. We find that the phase transition reduces from the Kosterlitz-Thouless transition to unconventional high-order phase transitions which feature the coexistence of properties Kosterliz-Thouless transition and the first-order phases transition simultaneously. As the fugacity increases further, phase transition evolves to the first-order phase transition. In addition, our results of dimer-dimer correlation functions and their corresponding structure factor functions computed by us show the evolution of decay correlation for different fugacity.
We generalize the Farey-Brocot partition to a twodimensional continued fraction algorithm and generalized Farey-Brocot nets. We give an asymptotic formula for the moments of order \beta.
Let $\mathbf{G}$ be the set of all finite or infinite increasing sequences of positive integers beginning with 1. For a sequence $S=\{s(n)\}, n\geq1,$ from $\mathbf{G},$ a positive number $N$ is called an exponentially $S$-number $(N\in E(S)),$ if all exponents in its prime power factorization are in $S.$ The author \cite{2} proved that, for every sequence $S\in \mathbf{G},$ the sequence of exponentially $S$-numbers has a density $h=h(E(S))\in [\frac{6}{\pi^2}, 1].$ In this paper we study the set $\{h(E(S)\}$ of all such densities.
The uncertainty principle generally prohibits determination of certain pairs of quantum mechanical observables with arbitrary precision and forms the basis of indeterminacy in quantum mechanics. It was Heisenberg who used the famous gamma-ray microscope thought experiment to illustrate this indeterminacy. A lower bound was set for the product of the measurement error of an observable and the disturbance caused by the measurement. Later on, the uncertainty relation was reformulated in terms of standard deviations, which focuses solely on indeterminacy of predictions and neglects unavoidable recoil in measuring devices. A correct formulation of the error-disturbance relation, taking recoil into account, is essential for a deeper understanding of the uncertainty principle. However, the validity of Heisenberg's original error-disturbance uncertainty relation is justifed only under limited circumstances. Another error-disturbance relation, derived by rigorous and general theoretical treatments of quantum measurements, is supposed to be universally valid. Here, we report a neutron optical experiment that records the error of a spin-component measurement as well as the disturbance caused on another spin-component measurement. The results confirm that both error and disturbance completely obey the new, more general relation but violate the old one in a wide range of an experimental parameter.
Zinc sulfide (ZnS) based materials are widely used in many applications. Yet, due to a lack of detailed knowledge of defect energy levels, the electrical properties and luminescence mechanisms in the materials still give rise to debate. Here, we report a first-principles study of native point defects and impurities in zincblende ZnS using hybrid density-functional calculations. We find that cation and anion vacancies and antisite defects introduce deep defect levels in the band gap and can act as donors or acceptors depending on the position of the Fermi level. The substitutional impurity Cu$_{\rm Zn}$ acts as a deep acceptor and thus does not contribute to p-type conductivity. Substitutional impurities Al$_{\rm Zn}$ and Cl$_{\rm S}$, on the other hand, are shallow donors. More importantly, we identify the isolated (i.e., unassociated) Cu$_{\rm Zn}$ as a source of the green luminescence observed in ZnS-based phosphors and Cu$_{\rm Zn}$$-$Al$_{\rm Zn}$ and Cu$_{\rm Zn}$$-$Cl$_{\rm S}$ defect complexes as sources of blue luminescence. The materials may have both green and blue emissions with the relative intensity dependent on the ratio between the unassociated defect and defect complex concentrations, which is also consistent with experimental observations.
The luminosity dependence of kinematical and isophotal properties of elliptical galaxies is investigated using numerical simulations of galaxy merging, combined with semi-analytical models of hierarchical structure formation. Mergers of spiral galaxies as the only formation mechanism for elliptical galaxies can neither reproduce the kinematical and photometric properties of very massive elliptical galaxies nor the change from rotationally flattened disky to anisotropic boxy systems with increasing luminosity. We present numerical simulations showing that binary mergers of early-type galaxies open an additional channel for the formation of anisotropic, slowly rotating and boxy ellipticals. Including this channel in a semi-analytical model we can successfully reproduce the observed trend that more luminous giant ellipticals are more boxy and less flattened by rotation. This trend can be strengthened by suppressing residual gas infall and star formation for galaxies with stellar bulge masses $M_* \geq 3 \times 10^{10} M_{\odot}$. Hence we propose that mergers of early-type galaxies play an important role for the assembly of massive elliptical galaxies.
We show how to construct a stick figure of lines in $\mathbb{P}^3$ using the Hadamard product of projective varieties. Then, applying the results of Migliore and Nagel, we use such stick figure to build a Gorenstein set of points with given $h-$vector ${\mathbf h}$. Since the Hadamard product is a coordinate-wise product, we show, at the end, how the coordinates of the points, in the Gorenstein set, can be directly determined.
We establish the Airy curve case of a conjecture of Gukov and Su{\l}kowski by reducing to Dijkgraaf-Verlinde-Verlinde Virasoro constraints satisfied by the intersection numbers on moduli spaces of algebraic curves.
We revisit the discovery outburst of the X-ray transient XTE J1550-564 during which relativistic jets were observed in 1998 September, and review the radio images obtained with the Australian Long Baseline Array, and lightcurves obtained with the Molonglo Observatory Synthesis Telescope and the Australia Telescope Compact Array. Based on HI spectra, we constrain the source distance to between 3.3 and 4.9 kpc. The radio images, taken some two days apart, show the evolution of an ejection event. The apparent separation velocity of the two outermost ejecta is at least 1.3c and may be as large as 1.9c; when relativistic effects are taken into account, the inferred true velocity is >0.8c. The flux densities appear to peak simultaneously during the outburst, with a rather flat (although still optically thin) spectral index of -0.2.
This paper is concerned with general spatially explicit versions of three stochastic models for the dynamics of money that have been introduced and studied numerically by statistical physicists: the uniform reshuffling model, the immediate exchange model and the model with saving propensity. All three models consist of systems of economical agents that consecutively engage in pairwise monetary transactions. Computer simulations performed in the physics literature suggest that, when the number of agents and the average amount of money per agent are large, the distribution of money at equilibrium approaches the exponential distribution for the first model, the gamma distribution with shape parameter two for the second model and a gamma distribution whose shape parameter depends on the saving propensity for the third model. The main objective of this paper is to give rigorous proofs of and extend these conjectures to generalizations of the first two models and a variant of the third model that include local rather than global interactions, i.e., instead of choosing the two interacting agents uniformly at random from the system, the agents are located on the vertex set of a general connected graph and can only interact with their neighbors.