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Related papers: A class of anisotropic diffusion-transport equatio…

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We resolve a long standing question regarding the suitable effective diffusion coefficient of the spherically-symmetric transport equation, which is valid at long times. To that end, we generalize a transport solution in three dimensions…

Statistical Mechanics · Physics 2024-02-01 Shay I. Heizler , Menahem Krief , Michael Assaf

We consider degenerate diffusion equations of the form $\partial_tp_t = \Delta f(p_t)$ on a bounded domain and subject to no-flux boundary conditions, for a class of nonlinearities $f$ that includes the porous medium equation. We derive for…

Probability · Mathematics 2022-10-31 Donghan Kim , Lane Chun Yeung

The process of diffusion is the most elementary stochastic transport process. Brownian motion, the representative model of diffusion, played a important role in the advancement of scientific fields such as physics, chemistry, biology and…

Statistical Mechanics · Physics 2015-08-11 Alexandre Bovet

The problem of anomalous diffusion in momentum (velocity) space is considered based on the master equation and the appropriate probability transition function (PTF). The approach recently developed by the author for coordinate space, is…

Statistical Mechanics · Physics 2015-05-18 S. A. Trigger

A physical-mathematical approach to anomalous diffusion may be based on generalized diffusion equations (containing derivatives of fractional order in space or/and time) and related random walk models. The fundamental solution (for the…

Statistical Mechanics · Physics 2007-09-25 Rudolf Gorenflo , Francesco Mainardi , Daniele Moretti , Gianni Pagnini , Paolo Paradisi

We study the Brownian dynamics and linear response of a particle with inertia moving in a 2-dimensional helical landscape imprinted on a cylindrical surface. In the harmonic well approximation, the deterministic motion separates into free…

Statistical Mechanics · Physics 2026-05-25 Debankur Bhattacharyya , Abraham Nitzan

We study a class of degenerate convection diffusion equations with a fractional nonlinear diffusion term. These equations are natural generalizations of anomalous diffusion equations, fractional conservations laws, local convection…

Analysis of PDEs · Mathematics 2011-07-28 Simone Cifani , Espen R. Jakobsen

We consider a spatially homogeneous advection-diffusion equation in which the diffusion tensor and drift velocity are time-independent, but otherwise general. We derive asymptotic expressions, valid at large distances from a steady point…

Chaotic Dynamics · Physics 2015-05-20 John Grant , Michael Wilkinson

In a recent paper [1] the scattering and transport of excess electrons in liquid argon in the hydrodynamic regime was investigated, generalizing the seminal works of Lekner and Cohen [2,3] with modern scattering theory techniques and…

Computational Physics · Physics 2017-10-02 G. J. Boyle , D. G. Cocks , W. J. Tattersall , R. P. McEachran , R. D. White

The coupling between advection and diffusion in position space can often lead to enhanced mass transport compared to diffusion without flow. An important framework used to characterize the long-time diffusive transport in position space is…

Fluid Dynamics · Physics 2024-10-10 Zhiwei Peng

In the first paper of this series, I investigated whether a wavefunction model of a heavy particle and a collection of light particles might generate "Brownian-Motion-Like" trajectories of the heavy particle. I concluded that it was…

Quantum Physics · Physics 2023-08-04 W. David Wick

Transport phenomena in porous media are commonplace in our daily lives. Examples and applications include heat and moisture transport in soils, baking and drying of food stuffs, curing of cement, and evaporation of fuels in wild fires. Of…

Chemical Physics · Physics 2013-05-13 Eric Sullivan

We investigate the density large deviation function for a multidimensional conservation law in the vanishing viscosity limit, when the probability concentrates on weak solutions of a hyperbolic conservation law conservation law. When the…

Statistical Mechanics · Physics 2018-03-14 Julien Barré , Cedric Bernardin , Raphaël Chetrite

The temporal Fokker-Planck equation is analytically integrated in an arbitrary number of spatial dimensions but with the 2D and 3D results highlighted. It is shown that a temporal power-law ansatz for the anisotropic diffusion coefficients…

Classical Physics · Physics 2013-06-27 Billy D. Jones

This paper deals with the deterministic particle method for the equation of porous media (with p = 2). We establish a convergence rate in the Wasserstein-2 distance between the approximate solution of the associated nonlinear transport…

Analysis of PDEs · Mathematics 2025-02-03 Amina Amassad , Datong Zhou

In Moln\'ar et al. [Phys. Rev. D 93, 114025 (2016)] the equations of anisotropic dissipative fluid dynamics were obtained from the moments of the Boltzmann equation based on an expansion around an arbitrary anisotropic single-particle…

Nuclear Theory · Physics 2016-12-07 Etele Molnár , Harri Niemi , Dirk H. Rischke

The adsorption phenomenon of neutral particles from the limiting surfaces of the sample in the Langmuir approximation is investigated. The diffusion equation regulating the redistribution of particles in the bulk is assumed to be of…

Mathematical Physics · Physics 2014-02-13 A Sapora , M Codegone , G Barbero , LR Evangelista

We derive the distribution of particle currents for a system of interacting active Brownian particles in the long time limit using large deviation theory and a weighted many body expansion. We find the distribution is non-Gaussian, except…

Statistical Mechanics · Physics 2018-12-19 Trevor GrandPre , David T. Limmer

For the Euler equations governing compressible isentropic fluid flow with a barotropic equation of state (where pressure is a function only of the density), local conservation laws in $n>1$ spatial dimensions are fully classified in two…

Fluid Dynamics · Physics 2015-05-13 Stephen C. Anco , Amanullah Dar

We study here the random diffusion model. This is a continuum model for a conserved scalar density field $\phi$ driven by diffusive dynamics. The interesting feature of the dynamics is that the {\it bare} diffusion coefficient $D$ is…

Soft Condensed Matter · Physics 2009-11-13 Gene F. Mazenko