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We present a set of uniform polynomial equations that provides multidimensional on-lattice higher-order models of the lattice Boltzmann theory, while keeping compact the number of discrete velocities. As examples, we explicitly derive two-…

Mathematical Physics · Physics 2020-11-10 Jae Wan Shim

We develop a kinetic-theory framework to investigate the steady rheology of a dilute gas interacting via a repulsive potential under uniform shear flow. Starting from the Boltzmann equation with a restitution coefficient that depends on the…

Soft Condensed Matter · Physics 2026-04-23 Yuria Kobayashi , Makoto R. Kikuchi , Shunsuke Iizuka , Satoshi Takada

In this paper we develop a random walk model on lattice for coordinate dependent diffusion at constant temperature in contact with a heat bath. We employ here a coordinate dependent waiting time of the random walker to make the diffusivity…

Statistical Mechanics · Physics 2020-08-27 Rohan Maniar , A. Bhattacharyay

Consider a particle diffusing in a confined volume which is divided into two equal regions. In one region the diffusion coefficient is twice the value of the diffusion coefficient in the other region. Will the particle spend equal…

Dynamical Systems · Mathematics 2015-06-04 P. F. Tupper , Xin Yang

We consider the linear dissipative Boltzmann equation describing inelastic interactions of particles with a fixed background. For the simplified model of Maxwell molecules first, we give a complete spectral analysis, and deduce from it the…

Analysis of PDEs · Mathematics 2009-02-20 Bertrand Lods , Clément Mouhot , Giuseppe Toscani

The Fokker-Planck equation for a heavy particle in a granular fluid is derived from the Liouville equation. The host fluid is assumed to be in its homogeneous cooling state and all interactions are idealized as smooth, inelastic hard…

Statistical Mechanics · Physics 2007-05-23 J. W. Dufty , J. J. Brey

We introduce a model of two coupled reaction-diffusion equations to describe the dynamics and propagation of flame fronts in random media. The model incorporates heat diffusion, its dissipation, and its production through coupling to the…

Condensed Matter · Physics 2016-08-15 N. Provatas , T. Ala-Nissila , M. Grant , K. R. Elder , L. Piché

A relation between the effective diffusion coefficient in a lattice with random site energies and random trasition rates and the macroscopic conductivity in a random resistor network allows for elucidating possible sources of anomalous…

Statistical Mechanics · Physics 2012-05-14 Federico Camboni , Igor M. Sokolov

We develop an agent-based model on a lattice to investigate territorial development motivated by markings such as graffiti, generalizing a previously-published model to account for $K$ groups instead of two groups. We then analyze this…

Physics and Society · Physics 2021-04-27 Abdulaziz Alsenafi , Alethea B. T. Barbaro

We propose a new semiparametric approach for modelling nonlinear univariate diffusions, where the observed process is a nonparametric transformation of an underlying parametric diffusion (UPD). This modelling strategy yields a general class…

Econometrics · Economics 2020-05-08 Ruijun Bu , Kaddour Hadri , Dennis Kristensen

The radiation (reaction, Robin) boundary condition for the continuum diffusion equation is widely used in chemical and biological applications to express reactive boundaries. The underlying trajectories of the diffusing particles are…

Mathematical Physics · Physics 2007-09-02 A. Singer , Z. Schuss , D. Holcman

We review some exact results for the motion of a tagged particle in simple models. Then, we study the density dependence of the self diffusion coefficient, $D_N(\rho)$, in lattice systems with simple symmetric exclusion in which the…

Statistical Mechanics · Physics 2015-06-25 A. Asselah , R. Brito , J. L. Lebowitz

Models of diffusion in white dwarfs universally rely on the coefficients calculated by Paquette et al. (1986). We present new calculations of diffusion coefficients based on an advanced microscopic theory of dense plasmas and a numerical…

Solar and Stellar Astrophysics · Physics 2014-10-29 D. Saumon , C. E. Starrett , J. Daligault

Self-diffusion along the longitudinal coordinate in a channel of varying cross section is considered. The starting point is the two-dimensional Enskog-Boltzmann-Lorentz kinetic equation with appropriated boundary conditions. It is…

Statistical Mechanics · Physics 2024-07-08 J. Javier Brey , M. I. García de Soria , P. Maynar

We develop a relativistic lattice Boltzmann (LB) model, providing a more accurate description of dissipative phenomena in relativistic hydrodynamics than previously available with existing LB schemes. The procedure applies to the…

Computational Physics · Physics 2015-06-12 M. Mendoza , I. Karlin , S. Succi , H. J. Herrmann

We study reaction-diffusion equations in cylinders with possibly nonlinear diffusion and possibly nonlinear Neumann boundary conditions. We provide a geometric Poincar\'e-type inequality and classification results for stable solutions, and…

Analysis of PDEs · Mathematics 2016-06-28 Serena Dipierro , Nicola Soave , Enrico Valdinoci

We construct a family of exactly solvable relativistic kinetic theories in $1+1$ dimensions whose hydrodynamic sector continuously interpolates between Fick's and Cattaneo's laws of diffusion. The interpolation is controlled by a single…

Nuclear Theory · Physics 2026-04-02 Lorenzo Gavassino

A generalisation of reaction diffusion systems and their travelling solutions to cases when the productive part of the reaction happens only on a surface in space or on a line on plane but the degradation and the diffusion happen in bulk…

Dynamical Systems · Mathematics 2022-01-05 Anton S. Zadorin

We treat a model of population dynamics in a periodic environment presenting a fast diffusion line. This phenomenon is modelled via a "road-field" system, which is a system of coupled reaction-diffusion equations set in domains of different…

Analysis of PDEs · Mathematics 2020-10-01 Elisa Affili

A quasi-two-dimensional system of hard spheres strongly confined between two parallel plates is considered. The attention is focussed on the macroscopic self-diffusion process observed when the system is looked from above or from below. The…

Statistical Mechanics · Physics 2020-01-09 J. Javier Brey , M. I. García de Soria , P. Maynar