ShantanuT01/DACTYL-Pretraining huggingface dataset:
We study an inhomogeneous sandpile model in which two different toppling rules are defined. For any site only one rule is applied corresponding to either the Bak, Tang and Wiesenfeld model {[}P.Bak, C. Tang, and K. Wiesenfeld, Phys. Rev. Lett. \textbf{59}, 381 (1987){]} or the Manna two-state sandpile model {[}S. S. Manna, J. Phys. A \textbf{24}, L363 (1991){]}. A parameter $c$ is introduced which describes a density of sites which are randomly deployed and where the stochastic Manna rules are applied. The results show that the avalanche area exponent $\tau_{a}$, avalanche size exponent $\tau_{s}$, and capacity fractal dimension $D_{s}$ depend on the density $c$. A crossover from multifractal scaling of the Bak, Tang, and Wiesenfeld model ($c=0$) to finite size scaling was found. The critical density $c$ is found to be in the interval $0<c<0.01$. These results demonstrate that local dynamical rules are important and can change the global properties of the model.
We study three CME/ICME events (2008 June 1-6, 2009 February 13-18, 2010 April 3-5) tracked from Sun to 1 AU in remote-sensing observations of STEREO Heliospheric Imagers and in situ plasma and magnetic field measurements. We focus on the ICME propagation in IP space that is governed by two forces, the propelling Lorentz force and the drag force. We address the question at which heliospheric distance range the drag becomes dominant and the CME gets adjusted to the solar wind flow. To this aim we analyze speed differences between ICMEs and the ambient solar wind flow as function of distance. The evolution of the ambient solar wind flow is derived from ENLIL 3D MHD model runs using different solar wind models, namely Wang-Sheeley-Arge (WSA) and MHD-Around-A-Sphere (MAS). Comparing the measured CME kinematics with the solar wind models we find that the CME speed gets adjusted to the solar wind speed at very different heliospheric distances in the three events under study: from below 30 Rs, to beyond 1 AU, depending on the CME and ambient solar wind characteristics. ENLIL can be used to derive important information about the overall structure of the background solar wind, providing more reliable results during times of low solar activity than during times of high solar activity. The results from this study enable us to get a better insight into the forces acting on CMEs over the IP space distance range, which is an important prerequisite in order to predict their 1 AU transit times.
A {\em Wakeford pairing} from $S$ onto $T$ is a bijection $\phi : S \to T$ such that $x\phi(x)\notin T,$ for every $x\in S.$ The number of such pairings will be denoted by $\mu(S,T)$.   Let $A$ and $ B$ be finite subsets of a group $G$ with $1\notin B$ and $|A|=|B|.$ Also assume that the order of every element of $B$ is $\ge |B|$. Extending results due to Losonczy and Eliahou-Lecouvey, we show that $\mu(B,A)\neq 0.$ Moreover we show that $\mu(B,A)\ge \min \{\frac{||B|+1}{3},\frac{|B|(q-|B|-1)}{2q-|B|-4}\},$ unless there is $a\in A$ such that $|Aa^{-1}\cap B|=|B|-1$ or $Aa^{-1}$ is a progression. In particular, either $\mu(B,B) \ge \min \{\frac{||B|+1}{3},\frac{|B|(q-|B|-1)}{2q-|B|-4}\},$ or for some $a\in B,$ $Ba^{-1}$ is a progression.
In this paper, we constuct the multi-point blowup solutions of self-similar type for the inviscid Burgers equation. The shape and blowup dynamics are precisely described. Moreover, the solutions we construct are stable under small perturbations on initial data restricted in a compact set.
We report experimental and theoretical studies of magnetic and related properties of ErRuSi compound. Various experimental techniques such as neutron diffraction, magnetization, magneto-thermal, magneto-transport, optical have been used to study the compound. Neutron diffraction shows ferromagnetic ordering at low temperatures with moments aligned in ab plane. Neutron diffraction and magnetization data show reduction in magnetic moment, which may be due to crystalline electric field effects at low temperatures. The compound shows good magnetocaloric properties with a low field adiabatic temperature change of 4.7 K, which is larger than that of many proposed materials for magnetic refrigeration at low temperatures. Magnetoresistance shows large negative value at 8 K, which changes its sign and increases in magnitude, with decrease in temperature and/or increase in field. The positive MR at low temperatures attributed to the Lorentz force effect. The electronic structure calculations accounting for electronic correlations of the 4f electrons of Er reproduces the ferromagnetic ordering and effective magnetic moment. Interband transitions between the Ru and Er d states and Er f states in one spin projection are found to form the main features of the measured optical conductivity in this compound.
The multifrequency resonance has been widely explored in some of the single-particle models, in which the modulating Rabi model has been most widely investigated. It has been found that with the diagonal periodic modulation, a steady dynamics can be realized in some well-defined discrete frequencies. These frequencies are independent of the off-diagonal couplings. In this work, we generalize this physics to the many-body seesaw realized using the tilted Bose-Hubbard model. We find that the wave function will recover to its initial condition when the modulation frequency is commensurate with the initial energy level spacing between the ground and the first excited levels. The period is determined by the driving frequency and commensurate ratio. In this case, the wave function will almost be restricted to the lowest two instantaneous energy levels. By projecting the wave function to these two relevant states, the dynamics is exactly the same as that for the spin precession dynamics and nutation dynamics around an oscillating axis. We map out the corresponding phase diagram and show that in the low-frequency regime the state is thermalized and in the strong modulation limit, the dynamics is determined by the effective Floquet Hamiltonian. The measurement of these dynamics from the mean position and mean momentum in phase space are also discussed. Our results provide a new thought about the multifrequency resonance in the many-body system.
In order to construct accurate point sources simulations at the frequencies relevant to 21-cm experiments, the angular correlation of radio sources must be taken into account. This paper presents a measurement of angular two-point correlation function, w(\theta), at 232 MHz from the MIYUN survey - tentative measurements of w(\theta) are also performed at 151 MHz. It is found that double power law with shape w(\theta) = A \theta^{-\gamma} fits the 232 MHz data well. For the angular lenght of 0.2 degrees < \theta < 0.6 degrees, \gamma ~ -1.12, and this value of slope is independent of the flux-density threshold; while for angular lenghts much greater than 0.6 degrees, \gamma has a shallower value of about -0.16. By comparing the results of this paper with previous measurements of w(\theta), it is discussed how w(\theta) changes with the change of frequency and completness limit.
This paper aims to address the problem of anomaly discovery in semantic segmentation. Our key observation is that semantic classification plays a critical role in existing approaches, while the incorrectly classified pixels are easily regarded as anomalies. Such a phenomenon frequently appears and is rarely discussed, which significantly reduces the performance of anomaly discovery. To this end, we propose a novel Distillation Comparison Network (DiCNet). It comprises of a teacher branch which is a semantic segmentation network that removed the semantic classification head, and a student branch that is distilled from the teacher branch through a distribution distillation. We show that the distillation guarantees the semantic features of the two branches hold consistency in the known classes, while reflect inconsistency in the unknown class. Therefore, we leverage the semantic feature discrepancy between the two branches to discover the anomalies. DiCNet abandons the semantic classification head in the inference process, and hence significantly alleviates the issue caused by incorrect semantic classification. Extensive experimental results on StreetHazards dataset and BDD-Anomaly dataset are conducted to verify the superior performance of DiCNet. In particular, DiCNet obtains a 6.3% improvement in AUPR and a 5.2% improvement in FPR95 on StreetHazards dataset, achieves a 4.2% improvement in AUPR and a 6.8% improvement in FPR95 on BDD-Anomaly dataset. Codes are available at https://github.com/zhouhuan-hust/DiCNet.
We present a detailed $^7$Li- and $^{31}$P-NMR study on single crystalline LiMnPO$_4$ in the paramagnetic and antiferromagnetic phase (AFM, $T_N \sim$ 34 K). This allows us to determine the spin directions in the field-induced spin-flop phase. In addition, the anisotropic dipolar hyperfine coupling tensor of the $^7$Li- and $^{31}$P-nuclei is also fully determined by orientation and temperature dependent NMR experiments and compared to the calculated values from crystal structure data. Deviations of the experimental values from the theoretical ones are discussed in terms of Mn disorder which is induced by Li-disorder. In fact, the disorder in the Mn-sublattice is directly revealed by our diffuse x-ray scattering data. The present results provide experimental evidence for the Li-diffusion strongly coupling to structural distortions within the MnPO$_4$ host, which is expected to significantly affect the Li-mobility as well as the performance of batteries based on this material.
We study a PDE model for dynamics of susceptible-infected interactions. The dispersal of susceptibles is via diffusion and repellent taxis as they move away from the increasing density of infected. The diffusion of infected is a nonlinear, possibly degenerating term in nondivergence form. We prove the existence of so-called weak-strong solutions in 1D for a positive susceptible initial population. For dimension $N\geq 2$ and nonnegative susceptible initial density we show the existence of supersolutions. Numerical simulations are performed for different scenarios and illustrate the space-time behaviour of solutions.
New equations are derived for meson and baryon Green's functions in a systematic method using the QCD Lagrangian and large N_c approximation as a starting point. The equations are shown to contain both confinement dynamics and chiral symmetry breaking. Linear Regge trajectories are demonstrated for the solutions.
Non-Abelian e/4 quasiparticles at 5/2 filling factor in a correlated two-dimensional electron gas have a proposed specific property in an interference measurement of their edge propagation: encircling an even number of localized e/4 quasiparticles allows expression of e/4 Aharonov-Bohm (A-B) oscillations, but suppression of these oscillations will occur with an odd number encircled. This picture is tested explicitly here in multiple interferometers of different areas. The encircled localized e/4 quasiparticle number near 5/2 filling factor is changed by sweeping B-field, and oscillations are observed in resistance near 5/2 of period specific to that device area for each interferometer. The product of the measured interferometric area of each device and the respective 5/2 resistance oscillation period is found to agree with the expected flux quanta addition needed for parity change in the localized e/4 number. This result shows a highly specific non-Abelian property of the quasiparticle excitations at 5/2 filling expressed in multiple interferometers.
We have studied the face-on, barred spiral M83 (NGC 5236) with Chandra. Eighty-one point sources are detected (above 3.5-sigma) in the ACIS S3 image: 15 of them are within the inner 16 arcsec region (starburst nucleus, resolved for the first time with Chandra), and 23 within the inner 60 arcsec (including the bar). The luminosity distributions of the sources in the inner 60 arcsec region (nucleus and stellar bar) is a single power law, which we interpret as due to continuous, ongoing star formation. Outside this inner region, there is a smaller fraction of bright sources, which we interpret as evidence of an aging population from a past episode of star formation. About 50% of the total emission in the nuclear region is unresolved; of this, about 70% can be attributed to hot thermal plasma, and we interpret the rest as due to unresolved point sources (eg, faint X-ray binaries). The unresolved X-ray emission also shows differences between the nuclear region and the spiral arms. In the nuclear region, the electron temperature of the thermal plasma is = 0.58 keV. In the spiral arms, the thermal component is at kT = 0.31 keV and a power-law component dominates at energies >~1 keV. The high abundance of C, Ne, Mg, Si and S with respect to Fe suggests that the interstellar medium is enriched and heated by core-collapse supernova explosions and winds from massive stars.
We identify the operational conditions for maximum power of a nanothermoelectric engine consisting of a single quantum level embedded between two leads at different temperatures and chemical potentials. The corresponding thermodynamic efficiency agrees with the Curzon-Ahlborn expression up to quadratic terms in the gradients, supporting the thesis of universality beyond linear response.
This report concerns the energy of neutron-matter for densities below $0.15 fm^{-3}$ and temperatures at and below $10 MeV$. Separable NN-interactions are obtained by inverse scattering from the experimental phase-shifts with specified momentum cut-offs $\Lambda$. Results of Brueckner-Bloch-DeDomicis as well as finite temperature Green's function calculations show independence of cut-off for $\Lambda \geq 3$. Agreement with the low-density virial expansion is found. Results of Hartree-Fock as well as second order calculations show considerable $\Lambda$-dependence and the agreement with the virial expansion is lost. The "best" first-order choice of $\Lambda$ is found to be $\sim 2.5 fm^{-1}$, which agrees with $V_{low k}$ studies. Reasonable agreement between the second order and the Brueckner results is also found for this value of $\Lambda$ except at low density. Only 2-body forces are used in this study.
We analyze a system composed of itinerant electrons and localized spins with on-site interactions representing the Hund's first rule. Properties of the system are studied rigorously on the infinite square lattice but the configurational space is restricted to the lowest-period phases only. Using exact expressions for the ground state energy an evolution of the phase diagram with an external magnetic field is determined. For a wide range of electron densities metamagnetic phase transitions are detected. It is shown that jumps of magnetization of the electrons at the metamagnetic transitions are much smaller than changes of magnetization of the localized spins.
We investigate the thermodynamical properties of nuclear matter in heavy ion collisions, in particular with respect to questions of thermodynamical instability, phase transitions and fragmentation. For this we analyze results of relativistic transport calculations of Au+Au collisons at intermediate energies, separately for spectator and participant matter. On one hand, we determine local thermodynamical variables from the analysis of the local momentum distribution; on the other, we analyze fragment energy spectra in a blast model scenario. We find that the spectator represents an instable, equilibrized fragmenting source, while in the participant no such common source can be identified. Our results compare well with experimental determinations of temperatures and flow velocities.
Weil has generalized the Riemann-von Mangoldt explicit formula linking the prime numbers with the zeros of the zeta function to the set-up of a general algebraic number field K and Dirichlet-Hecke L-function, revealing in the process the role played by the completions (finite and infinite) of K. We show how the local terms of these explicit formulae are explained by the dilaton invariant ``conductor operator'' log(|x|) + log(|y|). We also check Weil's positivity criterion under a support condition.
Using the Bethe ansatz method, we study the ground state properties of a $U\to\infty$ Anderson impurity in a ``gapless'' host, where a density of band states vanishes at the Fermi level $\epsilon_F$ as $|\epsilon-\epsilon_F|$. As in metals, the impurity spin is proven to be screened at arbitrary parameters of the system. However, the impurity occupancy as a function of the bare impurity energy is shown to acquire novel qualitative features which demonstrate a nonuniversal behavior of the system. The latter explains why the Kondo screening is absent (or exists only at quite a large electron-impurity coupling) in earlier studies based on scaling arguments.
A diagrammatic kinetic theory of density fluctuations in simple dense liquids at long times, described in the preceding paper, is applied to a high density Lennard-Jones liquid to calculate various equilibrium time correlation functions. The calculation starts from the general theory and makes two approximations. 1. The general diagrammatic expression for an irreducible memory kernel is approximated using a one-loop approximation. 2. The generalized Enskog projected propagator, which is required for the calculation, is approximated using a simple kinetic model for the hard sphere memory function. The coherent intermediate scattering function (CISF), the longitudinal current correlation function (LCCF), the transverse current correlation function (TCCF), the incoherent intermediate scattering function (IISF), and the incoherent longitudinal current correlation function (ILCCF) are calculated and compared with simulation results for the Lennard-Jones liquid at high density. The approximate theoretical results are in good agreement with the simulation data for the IISF for all wave vectors studied and for the CISF and LCCF for large wave vector. The approximate results are in poor agreement with the simulation data for the CISF, LCCF, and TCCF for small wave vectors because these functions are strongly affected by hydrodynamic fluctuations at small wave vector that are not well described by the simple kinetic model used. The possible implications of this approach for the study of liquids is discussed.
Let $\Gamma_n(\mathcal{\scriptstyle{O}}_\mathbb{K})$ denote the Hermitian modular group of degree $n$ over an imaginary-quadratic number field $\mathbb{K}$. In this paper we determine its maximal discrete extension in $SU(n,n;\mathbb{C})$, which coincides with the normalizer of $\Gamma_n(\mathcal{\scriptstyle{O}}_{\mathbb{K}})$. The description involves the $n$-torsion subgroup of the ideal class group of $\mathbb{K}$. This group is defined over a particular number field $\widehat{\mathbb{K}}_n$ and we can describe the ramified primes in it. In the case $n=2$ we give an explicit description, which involves generalized Atkin-Lehner involutions. Moreover we find a natural characterization of this group in $SO(2,4)$.
We have discovered a new, near-equal mass, eclipsing M dwarf binary from the Next Generation Transit Survey. This system is only one of 3 field age ($>$ 1 Gyr), late M dwarf eclipsing binaries known, and has a period of 1.74774 days, similar to that of CM~Dra and KOI126. Modelling of the eclipses and radial velocities shows that the component masses are $M_{\rm pri}$=0.17391$^{+0.00153}_{0.00099}$ $M_{\odot}$, $M_{\rm sec}$=0.17418$^{+0.00193}_{-0.00059}$ $M_{\odot}$; radii are $R_{\rm pri}$=0.2045$^{+0.0038}_{-0.0058}$ $R_{\odot}$, $R_{\rm sec}$=0.2168$^{+0.0047}_{-0.0048}$ $R_{\odot}$. The effective temperatures are $T_{\rm pri} = 2995\,^{+85}_{-105}$ K and $T_{\rm sec} = 2997\,^{+66}_{-101}$ K, consistent with M5 dwarfs and broadly consistent with main sequence models. This pair represents a valuable addition which can be used to constrain the mass-radius relation at the low mass end of the stellar sequence.
We give a sufficient condition for a class of tame compactified Landau-Ginzburg models in the sense of Katzarkov-Kontsevich-Pantev to satisfy some versions of their conjectures. We also give examples which satisfy the condition. The relations to the quantum D-modules of Fano manifolds and the original conjectures are explained in Appendices.
It is suggested in observations of supernova remnants that a number of large- and small-scale structures form at various points in the explosion. Multidimensional modeling of core-collapse supernovae has been undertaken since SN1987A, and both simulations and observations suggest/show that Rayleigh-Taylor instabilities during the explosion is a main driver for the formation of structure in the remnants.   We present a case study of structure formation in 3D in a \msol{15} supernova for different parameters. We investigate the effect of moderate asymmetries and different resolutions of the formation and morphology of the RT unstable region, and take first steps at determining typical physical quantities (size, composition) of arising clumps. We find that in this progenitor the major RT unstable region develops at the He/OC interface for all cases considered. The RT instabilities result in clumps that are overdense by 1-2 orders of magnitude with respect to the ambient gas, have size scales on the level of a few % of the remnant diameter, and are not diffused after the first $\sim30$ yrs of the remnant evolution, in the absence of a surrounding medium.
This paper develops asymptotic approximations of $P(\int_Te^{f(t)}\,dt>b)$ as $b\rightarrow\infty$ for a homogeneous smooth Gaussian random field, $f$, living on a compact $d$-dimensional Jordan measurable set $T$. The integral of an exponent of a Gaussian random field is an important random variable for many generic models in spatial point processes, portfolio risk analysis, asset pricing and so forth. The analysis technique consists of two steps: 1. evaluate the tail probability $P(\int_{\Xi}e^{f(t)}\,dt>b)$ over a small domain $\Xi$ depending on $b$, where $\operatorname {mes}(\Xi)\rightarrow0$ as $b\rightarrow \infty$ and $\operatorname {mes}(\cdot)$ is the Lebesgue measure; 2. with $\Xi$ appropriately chosen, we show that $P(\int_Te^{f(t)}\,dt>b)=(1+o(1))\operatorname{mes}(T)\times \operatorname{mes}^{-1}(\Xi)P(\int_{\Xi}e^{f(t)}\,dt>b)$.
This is a draft chapter for a book, entitled Physical Processes in Circumstellar Disks around Young Stars, which is scheduled for publication by the University of Chicago Press as one of its Theoretical Astrophysics Series volumes. Sect. 1 presents the motivation for considering the effects of a large-scale, ordered magnetic field on the formation and evolution of protostellar disks. Sect. 2 outlines the physical principles that underlie the magnetohydrodynamics of disks that are threaded by such a field. Sect. 3 discusses the formation and early evolution of disks that result from the collapse of a rotating molecular cloud core that is coupled to the insterstellar magnetic field. Sect. 4 reviews the observational evidence for the disk--wind connection and describes the structure of magnetically accelerated disk outflows, focusing on centrifugally driven winds; it then goes on to discuss the equilibrium and stability properties of weakly ionized protostellar accretion disks in which the transport of angular momentum is dominated by a wind of this type. Sect. 5 considers the coupling between the central protostar and the surrounding disk through the protostellar magnetic field, covering, in turn, the phenomenology, basic concepts, and results of numerical simulations. The chapter is summarized in Sect. 6, which also contains a discussion of future research directions.