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We present an improved model and theory for time-causal and time-recursive spatio-temporal receptive fields, obtained by a combination of Gaussian receptive fields over the spatial domain and first-order integrators or equivalently…

计算机视觉与模式识别 · 计算机科学 2021-01-25 Tony Lindeberg

Gaussian random fields (GRFs) constitute an important part of spatial modelling, but can be computationally infeasible for general covariance structures. An efficient approach is to specify GRFs via stochastic partial differential equations…

统计方法学 · 统计学 2016-08-11 Geir-Arne Fuglstad , Finn Lindgren , Daniel Simpson , Håvard Rue

The field induced quantum phase transitions in the disorder-free and disordered samples of the spin ladder material (CH_3)_2CHNH_3Cu(Cl_{1-x}Br_x)_3 are studied using magnetic calorimetry and magnetic neutron diffraction on single crystal…

强关联电子 · 物理学 2018-06-06 G. S. Perren , W. E. A. Lorenz , E. Ressouche , A. Zheludev

Harmonic generation in the scattered fields produced by a dielectric sphere coated with a time-varying conductive shell is studied using a Mie theory approach hybridized with conversion matrix methods. Analytic results are derived for plane…

光学 · 物理学 2022-09-21 Kurt Schab , Bradley Shirley , K. C. Kerby-Patel

We generate new spherical and time-dependent solutions of viable Horndeski gravity by disforming a solution of the Einstein equations with scalar field source and positive cosmological constant. They describe dynamical objects embedded in…

广义相对论与量子宇宙学 · 物理学 2022-10-05 Reza Saadati , Andrea Giusti , Valerio Faraoni , Fatimah Shojai

Space-time coordinates in DSR theories with two invariant scales based on a dispersion relation with an energy independent speed of light are introduced by the demand, that boost and rotation generators are invariant under a transformation…

广义相对论与量子宇宙学 · 物理学 2007-05-23 Clemens Heuson

We consider two models of random diffusion in random environment in two dimensions. The first example is the self-repelling Brownian polymer, this describes a diffusion pushed by the negative gradient of its own occupation time measure…

概率论 · 数学 2010-12-30 Balint Toth , Benedek Valko

General equations of the unified field theory, obtained using the curved and torsional space-time, are presented. They contain only independent geometrical parameters (metric and connections) of the metric-affine space, and describe the…

综合物理 · 物理学 2026-01-22 Alex Karpelson

A review is given on some recent developments in the theory of the Ising model in a random field. This model is a good representation of a large number of impure materials. After a short repetition of earlier arguments, which prove the…

统计力学 · 物理学 2008-02-03 T. Nattermann

Spherically symmetric time-dependent solutions for the 5D system of a scalar field canonically coupled to gravity are obtained and identified as an extension of recent results obtained by Ahmed, Grzadkowskia and Wudkab. The corresponding…

广义相对论与量子宇宙学 · 物理学 2014-12-31 Alex E. Bernardini , R. T. Cavalcanti , Roldao da Rocha

The perturbation of a magnetostatic field by a toroid made of a homogeneous anisotropic magnetic material was formulated using the solutions of the Laplace equation in the toroidal coordinate system. That was straightforward in the region…

经典物理 · 物理学 2025-04-11 Hamad M. Alkhoori , Akhlesh Lakhtakia , Nikolaos L. Tsitsas

We discuss the formulation of classical field theoretical models on $n$-dimensional noncommutative space-time defined by a generic associative star product. A simple procedure for deriving conservation laws is presented and applied to field…

高能物理 - 理论 · 物理学 2018-12-31 Daniel N. Blaschke , Francois Gieres , Stefan Hohenegger , Manfred Schweda , Michael Wohlgenannt

The scattering of electromagnetic waves from obstacles with wave-material interaction in thin layers on the surface is described by generalized impedance boundary conditions, which provide effective approximate models. In particular, this…

数值分析 · 数学 2022-02-04 Jörg Nick , Balázs Kovács , Christian Lubich

We introduce an elliptic extension of Dyson's Brownian motion model, which is a temporally inhomogeneous diffusion process of noncolliding particles defined on a circle. Using elliptic determinant evaluations related to the reduced affine…

概率论 · 数学 2015-08-18 Makoto Katori

This paper investigates solutions of hyperbolic diffusion equations in $\mathbb{R}^3$ with random initial conditions. The solutions are given as spatial-temporal random fields. Their restrictions to the unit sphere $S^2$ are studied. All…

We employ renewal processes to characterize the spatiotemporal dynamics of an active Brownian particle under stochastic orientational resetting. By computing the experimentally accessible intermediate scattering function (ISF) and…

软凝聚态物质 · 物理学 2024-05-14 Yanis Baouche , Thomas Franosch , Matthias Meiners , Christina Kurzthaler

The generation of non-separable, physically motivated covariance functions is a theme of ongoing research interest, given that only a few classes of such functions are available. We construct a non-separable space-time covariance function…

统计方法学 · 统计学 2016-12-20 Dionissios T. Hristopulos , Ivi C. Tsantili

Transport and scattering phenomena in open quantum-systems with a continuous energy spectrum are conveniently solved using the time-dependent Schrodinger equation. In the time-dependent picture, the evolution of an initially localized…

量子物理 · 物理学 2011-05-13 Tobias Kramer

We derive the equation for the evolution of the curvature perturbation on the comoving time slice, $\mathcal{R}_c$, in the presence of anisotropic and non-adiabatic terms in the energy-momentum tensor of matter fields. The equation is…

广义相对论与量子宇宙学 · 物理学 2019-11-21 Atsushi Naruko , Antonio Enea Romano , Misao Sasaki , Sergio Vallejo Penas

We subject the stationary solutions of inviscid and axially symmetric rotational accretion to a time-dependent radial perturbation, which includes nonlinearity to any arbitrary order. Regardless of the order of nonlinearity, the equation of…

高能天体物理现象 · 物理学 2015-06-05 Soumyajit Bose , Anindya Sengupta , Arnab K. Ray