ShantanuT01/DACTYL-Pretraining huggingface dataset:
We present a novel adaptive online learning (AOL) framework to predict human movement trajectories in dynamic video scenes. Our framework learns and adapts to changes in the scene environment and generates best network weights for different scenarios. The framework can be applied to prediction models and improve their performance as it dynamically adjusts when it encounters changes in the scene and can apply the best training weights for predicting the next locations. We demonstrate this by integrating our framework with two existing prediction models: LSTM [3] and Future Person Location (FPL) [1]. Furthermore, we analyze the number of network weights for optimal performance and show that we can achieve real-time with a fixed number of networks using the least recently used (LRU) strategy for maintaining the most recently trained network weights. With extensive experiments, we show that our framework increases prediction accuracies of LSTM and FPL by ~17% and 28% on average, and up to ~50% for FPL on the worst case while achieving real-time (20fps).
I use HST spectrophotometry to analyze the calibration of 3 optical photometry systems: Tycho-2 B_T V_T, Str\"omgren u v b y, and Johnson U B V. For Tycho-2, I revisit the analysis of Ma\'iz Apell\'aniz (2005) to include the new recalibration of grating/aperture corrections, vignetting, and charge transfer inefficiency effects produced by the STIS group and to consider the consequences of both random and systematic uncertainties. The new results reaffirm the good quality of both the Tycho-2 photometry and the HST spectrophotometry, but yield a slightly different value for ZP_B_T-V_T. For the Str\"omgren v, b, and y and the Johnson B and V filters I find that the published sensitivity curves are consistent with the available photometry and spectrophotometry and I derive new values for the associated ZP_b-y, ZP_m_1, and ZP_B-V. The situation is different for the Str\"omgren u and the Johnson U filters. There I find that the published sensitivity curves yield results that are inconsistent with the available photometry and spectrophotometry, likely caused by an incorrect treatment of atmospheric effects in the short-wavelength end. I reanalyze the data to produce new average sensitivity curves for those two filters and new values for ZP_c_1 and ZP_U-B. The new computation of synthetic U-B and B-V colors uses a single B sensitivity curve, which eliminates the previous unphysical existence of two different definitions. Finally, I find that if one uses values from the literature where uncertainties are not given, reasonable estimates for these are 1-2% for Str\"omgren b-y, m_1, and c_1 and 2-3% for Johnson B-V and U-B. The use of the results in this article should lead to a significant reduction of systematic errors when comparing synthetic photometry models with real colors and indices.
Charge order is now accepted as an integral constituent of cuprate high-temperature superconductors, one that is intimately related to other instabilities in the phase diagram including antiferromagnetism and superconductivity. Unlike nesting-induced Peierls-like density waves, the charge correlations in the CuO2 planes have been predicted to display a rich momentum space topology depending on the detailed fermiology of the system. However, to date charge order has only been observed along the high-symmetry Cu-O bond directions. Here, using resonant soft X-ray scattering, we investigate the evolution of the full momentum space topology of charge correlations in Ln2CuO4 (Ln=Nd, Pr) as a function of intrinsic electron doping. We report that, upon electron doping the parent Mott insulator, charge correlations first emerge in a hitherto-unobserved form, with full (Cinf) rotational symmetry in momentum-space. At higher doping levels, the orientation of charge correlations is sharply locked to the Cu-O bond high-symmetry directions, restoring a more conventional bidirectional charge order with enhanced correlation lengths. Through charge susceptibility calculations, we closely reproduce the drastic evolution in the topology of charge correlations across an antiferromagnetic quantum phase transition, highlighting the interplay between spin and charge degrees of freedom in electron-doped cuprates. Finally, using the established link between charge correlations and the underlying fermiology, we propose a revised phase diagram of Ln2CuO4 with a superconducting region extending toward the Mott limit.
We study null 1/4 BPS deformations of flat domain wall solutions (NDDW) in N=2, d=5 gauged supergravity with hypermultiplets and vector multiplets coupled. These are uncharged time-dependent configurations and contain as special case, 1/2 supersymmetric flat domain walls (DW), as well as 1/2 BPS null solutions of the ungauged supergravity. Combining our analysis with the classification method initiated by Gauntlett et al., we prove that all the possible deformations of the DW have origin in the hypermultiplet sector or/and are null. Here, we classify all the null deformations: we show that they naturally organize themselves into "gauging" (v-deformation) and "non gauging" (u-deformation). They have different properties: only in presence of v-deformation is the solution supported by a time-dependent scalar potential. Furthermore we show that the number of possible deformations equals the number of matter multiplets coupled. We discuss the general procedure for constructing explicit solutions, stressing the crucial role taken by the integrability conditions of the scalars as spacetime functions. Two analytical solutions are presented. Finally, we comment on the holographic applications of the NDDW, in relation to the recently proposed time-dependent AdS/CFT.
We construct a moduli space for Riemann surfaces that is universal in the sense that it represents compact Riemann surfaces of any finite genus. This moduli space is stratifed according to genus, and it carries a metric and a measure that induce a Riemannian metric and a finite volume measure on each stratum. Applications to the Plateau-Douglas problem for minimal surfaces of varying genus and to the partition function of Bosonic string theory are outlined. The construction starts with a universal moduli space of Abelian varieties. This space carries a structure of an infinite dimensional locally symmetric space which is of interest in its own right. The key to our construction of the universal moduli space then is the Torelli map that assigns to every Riemann surface its Jacobian and its extension to the Satake-Baily-Borel compactifications.
In a previous paper, we studied the Higgs pair production in the standard model with the reaction $e^{+}e^{-}\to t \bar t HH$. Based on this, we study the Higgs pair production via $e^{+}e^{-}\to b \bar b HH$. We evaluate the total cross section of $b\bar bHH$ and calculate the number total of events considering the complete set of Feynman diagrams at tree-level, and compare this process with the process $e^{+}e^{-}\to t \bar t HH$. The numerical computation is done for the energy which is expected to be available at a possible Next Linear $e^{+}e^{-}$ Collider with a center-of-mass energy $800, 1000, 1600$ $GeV$ and luminosity 1000 $fb^{-1}$.
This work presents a general unifying theoretical framework for quantum non-equilibrium systems. It is based on a re-statement of the dynamical problem as one of inferring the distribution of collision events that move a system toward thermal equilibrium from an arbitrary starting distribution. Using a form based on maximum entropy for this transition distribution leads to a statistical description of open quantum systems with strong parallels to the conventional, maximum-entropy, equilibrium thermostatics. A precise form of the second law of thermodynamics can be stated for this dynamics at every time-point in a trajectory. Numerical results are presented for low-dimensional systems interacting with cavity fields. The dynamics and stationary state are compared to a reference model of a weakly coupled oscillator plus cavity supersystem thermostatted by periodic partial measurements. Despite the absence of an explicit cavity in the present model of open quantum dynamics, both the relaxation rates and stationary state properties closely match the reference. Additionally, the time-course of energy exchange and entropy increase is given throughout an entire measurement process for a single spin system. The results show the process to be capable of initially absorbing heat when starting from a superposition state, but not from an isotropic distribution. Based on these results, it is argued that logical inference in the presence of environmental noise is sufficient to resolve the paradox of wavefunction collapse.
The identification of the solar-like oscillation modes, as measured by asteroseismology, is a necessary requirement in order to infer the physical properties of the interior of the stars. Difficulties occur when a large number of modes of oscillations with a low signal-to-noise ratio are observed. In those cases, it is of common use to apply a likelihood-ratio test to discriminate between the possible scenarios. We present here a statistical analysis of the likelihood-ratio test and discuss its accuracy to identify the correct modes. We use the AsteroFLAG artificial stars, simulated over a range of magnitude, inclination angle, and rotation rate. We show that the likelihood-ratio test is appropriate up to a certain magnitude (signal-to-noise ratio).
Context: Recently, the CoRoT target HD 175272 (F5V), which shows a weak signal of solar-like oscillations, was modelled by a differential asteroseismic analysis (Ozel et al. 2013) relative to a seismically similar star, HD 181420 (F2V), for which there is a clear signature of solar-like oscillations. The results provided by Ozel et al. (2013) indicate the possibility of HD 175272 having subsolar mass, while being of the order of 1000 K hotter than the Sun. This seems unphysical -- standard stellar evolution theory generally does not predict solar-metallicity stars of subsolar mass to be hotter than about 6000K -- and calls for a reanalysis of this star. Aims: We aim to compare the performance of differential asteroseismic analysis with that of grid-based modelling. Methods: We use two sets of stellar model grids and two grid-fitting methods to model HD 175272 and HD 181420. Results: We find that we are able to model both stars with parameters that are both mutually compatible and comparable with other modelling efforts. Hence, with modest spectroscopic and asteroseismic inputs, we obtain reasonable estimates of stellar parameters. In the case of HD 175272, the uncertainties of the stellar parameters from our grid-based modelling are smaller, and hence more physical, than those reported in the differential analysis. Conclusions: Grid-based modelling provides more precise and more realistic results than obtained with differential seismology.
Additive processes are obtained from L\'{e}vy ones by relaxing the condition of stationary increments, hence they are spatially (but not temporally) homogeneous. By analogy with the case of time-homogeneous Markov processes, one can define an infinitesimal generator, which is, of course, a time-dependent operator. Additive versions of stable and Gamma processes have been considered in the literature. We introduce here time-inhomogeneous generalizations of the well-known geometric stable process, defined by means of time-dependent versions of fractional pseudo-differential operators of logarithmic type. The local L\'{e}vy measures are expressed in terms of Mittag-Leffler functions or $H$-functions with time-dependent parameters.
In [\href{http://www.sciencedirect.com/science/article/pii/037596019290711T}{Phys. Lett. A {\bf 166}, 293 (1992)}] Popescu characterized nonlocality of pure $n$-partite entangled systems by studying bipartite violation of local realism when $n-2$ number of parties perform projective measurements on their particles. A pertinent question in this scenario is whether similar characterization is possible for $n$-partite mixed entangled states also. In the present work we have followed an analogous approach so as to explore whether given a tripartite mixed entangled state the conditional bipartite states obtained by performing projective measurement on the third party, demonstrate a weaker form of nonlocality, quantum steering. We also compare this new phenomenon of conditional steering with existing notions of tripartite correlations. Interestingly the tripartite state need not be genuinely entangled to demonstrate conditional steering.
The thermalisation rate for long wavelength fluctuations of the gauge field in the abelian Higgs model is calculated from the imaginary part of the self energy. The calculation is performed for both the symmetric and symmetry broken phase of the theory.
In this paper we study qualitative properties of global minimizers of the Ginzburg-Landau energy which describes light-matter interaction in the theory of nematic liquid crystals near the Friedrichs transition. This model is depends on two parameters: $\epsilon>0$ which is small and represents the coherence scale of the system and $a\geq 0$ which represents the intensity of the applied laser light. In particular we are interested in the phenomenon of symmetry breaking as $a$ and $\epsilon$ vary. We show that when $a=0$ the global minimizer is radially symmetric and unique and that its symmetry is instantly broken as $a>0$ and then restored for sufficiently large values of $a$. Symmetry breaking is associated with the presence of a new type of topological defect which we named the shadow vortex. The symmetry breaking scenario is a rigorous confirmation of experimental and numerical results obtained in our earlier work.
We consider wide ballistic microcontacts with electron-electron scattering in the leads and calculate electric noise and nonlinear conductance in them. Due to a restricted geometry the collisions of electrons result in a shot noise even though they conserve the total momentum of electrons. We obtain the noise and the conductivity for arbitrary relations between voltage V and temperature T. The positive inelastic correction to the Sharvin conductance is proportional to T at low voltages eV << T, and to |V| at high voltages. At low voltages the noise is defined by the Nyquist relation and at high voltages the noise is related with the inelastic correction to the current by the Shottky formula S_{in} = 2eI_{in}.
We study the interstellar medium (ISM) properties as a function of the molecular gas size for 77 infrared-selected galaxies at $z \sim 1.3$. Molecular gas sizes are measured on ALMA images that combine CO(2-1), CO(5-4) and underlying continuum observations, and include CO(4-3), CO(7-6)+[CI]($^3 P_2-^3P_1$), [CI]($^3 P_1-^3P_0$) observations for a subset of the sample. The $\gtrsim 46 \%$ of our galaxies have a compact molecular gas reservoir, and lie below the optical disks mass-size relation. Compact galaxies on and above the main sequence have higher CO excitation and star formation efficiency than galaxies with extended molecular gas reservoirs, as traced by CO(5-4)/CO(2-1) and CO(2-1)/$L_{\rm IR, SF}$ ratios. Average CO+[CI] spectral line energy distributions indicate higher excitation in compacts relative to extended sources. Using CO(2-1) and dust masses as molecular gas mass tracers, and conversion factors tailored to their ISM conditions, we measure lower gas fractions in compact main-sequence galaxies compared to extended sources. We suggest that the sub-millimetre compactness, defined as the ratio between the molecular gas and the stellar size, is an unavoidable information to be used with the main sequence offset to describe the ISM properties of galaxies, at least above $M_{\star} \geqslant 10^{10.6}$ M$_{\odot}$, where our observations fully probe the main sequence scatter. Our results are consistent with mergers driving the gas in the nuclear regions, enhancing the CO excitation and star formation efficiency. Compact main-sequence galaxies are consistent with being an early post-starburst population following a merger-driven starburst episode, stressing the important role of mergers in the evolution of massive galaxies.
In the slow diffusion case unbounded supersolutions of the porous medium equation are of two totally different types, depending on whether the pressure is locally integrable or not. This criterion and its consequences are discussed.
We prove sharp estimates for the decay in time of solutions to a rather general class of non-local in time subdiffusion equations on a bounded domain subject to a homogeneous Dirichlet boundary condition. Important special cases are the time-fractional and ultraslow diffusion equation, which have seen much interest during the last years, mostly due to their applications in the modeling of anomalous diffusion. We study the case where the equation is in divergence form with bounded measurable coefficients. Our proofs rely on energy estimates and make use of a new and powerful inequality for integro-differential operators of the form $\partial_t (k\ast \cdot)$. The results can be generalized to certain quasilinear equations. We illustrate this by looking at the time-fractional $p$-Laplace and porous medium equation. Here it turns out that the decay behaviour is markedly different from that in the classical parabolic case.
There is a striking paucity of hydrogen-rich (DA) white dwarfs (WDs) relative to their hydrogen-deficient (non-DA) counterparts at the very hot end of the WD cooling sequence. The three hottest known DAs (surface gravity log g $\geq$ 7.0) have effective temperatures around Teff = 140,000 K, followed by only five objects in the range 104,000 - 120,000 K. They are by far outnumbered by forty non-DAs with Teff = 100,000 - 250,000 K, giving a DA/non-DA ratio of 0.2. In contrast, this ratio is the inverse of that for the cooler WDs. One reason for this discrepancy could be uncertainties in the temperature determination of hot DAs using Balmer-line spectroscopy. Recent investigations involving metal-ionization balances in ultraviolet (UV) spectra indeed showed that the temperatures of some DAs were underestimated, but the paucity of extremely hot DAs prevailed. Here we present the results of a UV spectral analysis of one of the three hottest DAs, PG0948+534. We find that its temperature was strongly overestimated by recent Balmer line analyses. We correct it downward to 105,000 $\pm$ 5000 K, aggravating the hot-DA paucity. The Balmer-line problem encountered previously is not resolved by our non-LTE line-blanketed model atmospheres. We speculate that it might be related to the possible presence of a magnetosphere. This is supported by the V-band variability that shows a period of P=3.45 d (amplitude 0.19 mag), which we interpret as the star's rotation period. The metal abundances in PG0948+534 are affected by atomic diffusion and we conclude that the onset of diffusion in hot DAs occurs when they cool below Teff about 105,000 K. We discuss the possibility that the paucity of very hot DAs is a consequence of their fast evolutionary rate.
We study different mechanisms by which the speed of primordial curvature perturbations can produce an enhancement of the curvature spectrum, which could lead to the production of primordial black holes (PBH). One possibility is the growth of the sound speed in single scalar field models, which can induce super-horizon growth of curvature perturbations. The other is the momentum dependent effective sound (MESS) of curvature perturbations, which can arise in multi-fields models or modified gravity theories.   Future gravitational waves observatories such as LISA will allow to set constraints of the space and time dependency of the sound speed, and on the different theoretical scenarios from which it can originate.
The spatial variations of the gas-to-dust ratio (GDR) provide constraints on the chemical evolution and lifecycle of dust in galaxies. We examine the relation between dust and gas at 10-50 pc resolution in the Large and Small Magellanic Clouds (LMC and SMC) based on Herschel far-infrared (FIR), H I 21 cm, CO, and Halpha observations. In the diffuse atomic ISM, we derive the gas-to-dust ratio as the slope of the dust-gas relation and find gas-to-dust ratios of 380+250-130 in the LMC, and 1200+1600-420 in the SMC, not including helium. The atomic-to-molecular transition is located at dust surface densities of 0.05 Mo pc-2 in the LMC and 0.03 Mo pc-2 in the SMC, corresponding to AV ~ 0.4 and 0.2, respectively. We investigate the range of CO-to-H2 conversion factor to best account for all the molecular gas in the beam of the observations, and find upper limits on XCO to be 6x1020 cm-2 K-1 km-1 s in the LMC (Z=0.5Zo) at 15 pc resolution, and 4x 1021 cm-2 K-1 km-1 s in the SMC (Z=0.2Zo) at 45 pc resolution. In the LMC, the slope of the dust-gas relation in the dense ISM is lower than in the diffuse ISM by a factor ~2, even after accounting for the effects of CO-dark H2 in the translucent envelopes of molecular clouds. Coagulation of dust grains and the subsequent dust emissivity increase in molecular clouds, and/or accretion of gas-phase metals onto dust grains, and the subsequent dust abundance (dust-to-gas ratio) increase in molecular clouds could explain the observations. In the SMC, variations in the dust-gas slope caused by coagulation or accretion are degenerate with the effects of CO-dark H2. Within the expected 5--20 times Galactic XCO range, the dust-gas slope can be either constant or decrease by a factor of several across ISM phases. Further modeling and observations are required to break the degeneracy between dust grain coagulation, accretion, and CO-dark H2.
We study tail behaviour of the distribution of the area under the positive excursion of a random walk which has negative drift and heavy-tailed increments. We determine the asymptotics for tail probabilities for the area.
We present a unified description of the spontaneous symmetry breaking and its associated bosons in fermion field theory. There is no Goldstone boson in the fermion field theory models of Nambu-Jona-Lasinio, Thirring and QCD$_2$ after the chiral symmetry is spontaneously broken in the new vacuum. The defect of the Goldstone theorem is clarified, and the "massless boson" predicted by the theorem is virtual and corresponds to just a $free$ massless fermion and antifermion pair. Further, we discuss the exact spectrum of the Thirring model by the Bethe ansatz solutions, and the analytical expressions of all the physical observables enable us to understand the essence of the spontaneous symmetry breaking in depth. Also, we examine the boson spectrum in QCD$_2$, and show that bosons always have a finite mass for $SU(N_c)$ colors. The problem of the light cone prescription in QCD$_2$ is discussed, and it is shown that the trivial light cone vacuum is responsible for the wrong prediction of the boson mass.
In this paper, the effectiveness utilization of agriculture wastes and industrial wastes in the composites cement has been studied in terms of physical and mechanical properties. Twenty weight percent of fly ash and eighty weight percent of sand were added to the composite cement. The different weight percent of coconut fiber (3 wt. %, 6 wt. %, 9 wt. %, 12 wt. % and 15 wt. %) was added in the composition as reinforcement for cement composites. Water to cement ratio ranging from 0.55 to 0.70 was added into the cement composites accordingly to maintain its workability. Then the cement composites were cured in water for 7, 14 and 28 days respectively. Results for physical properties (density, moisture content, water absorption) and mechanical properties (compressive strength, modulus of rupture) are presented.