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We investigate the dynamics of an overdamped Brownian particle moving in a washboard potential with space dependent friction coefficient. Analytical expressions have been obtained for current and diffusion coefficient. We show that the…

Statistical Mechanics · Physics 2009-11-07 Debasis Dan , A. M. Jayannavar

Diffusion of a two component fluid is studied in the framework of differential equations, but where these equations are systematically derived from a well-defined microscopic model. The model has a finite carrying capacity imposed upon it…

Statistical Mechanics · Physics 2015-06-04 D. Fanelli , A. J. McKane , G. Pompili , B. Tiribilli , M. Vassalli , T. Biancalani

We study the main properties of the solution of a Fokker-Planck equation characterized by a variable diffusion coefficient and a polynomial superlinear drift, modeling the formation of consensus in a large interacting system of individuals.…

Analysis of PDEs · Mathematics 2025-04-18 Giuseppe Toscani , Mattia Zanella

A {\em propagation-dispersion equation} is derived for the first passage distribution function of a particle moving on a substrate with time delays. The equation is obtained as the continuous limit of the {\em first visit equation}, an…

Statistical Mechanics · Physics 2007-05-23 Jean Pierre Boon , Patrick Grosfils , James F. Lutsko

We investigate a model, inspired by (Johnston et al., Sci. Rep., 7:42134, 2017), to describe the movement of a biological population which consists of isolated and grouped organisms. We introduce biases in the movements and then obtain a…

Analysis of PDEs · Mathematics 2023-04-06 Diego Berti , Andrea Corli , Luisa Malaguti

We present a method how to estimate from experimental data of a turbulent velocity field the drift and the diffusion coefficient of a Fokker-Planck equation. It is shown that solutions of this Fokker-Planck equation reproduce with high…

chao-dyn · Physics 2007-05-23 Ch. Renner , B. Reisner , St. Lück , J. Peinke , R. Friedrich

We show that when Brownian motion takes place in a heterogeneous medium, the presence of local forces and transport coefficients leads to deviations from a Gaussian probability distribution that make that the ratio between forward and…

Soft Condensed Matter · Physics 2016-12-21 Paolo Malgaretti , Ignacio Pagonabarraga Miguel J. Rubi

General self-consistent expressions for the coefficients of diffusion and dynamical friction in a stable, bound, multicomponent self-gravitating and inhomogeneous system are derived. They account for the detailed dynamics of the colliding…

Astrophysics of Galaxies · Physics 2017-06-20 Jean Heyvaerts , Jean-Baptiste Fouvry , Pierre-Henri Chavanis , Christophe Pichon

This paper is interested in the description of the density of particles evolving according to some optimal policy of an impulse control problem. We first fix sets on which the particles jump and explain how we can characterize such a…

Analysis of PDEs · Mathematics 2018-07-03 Charles Bertucci

We consider a semi-linear advection equation driven by a highly-oscillatory space-time Gaussian random field, with the randomness affecting both the drift and the nonlinearity. In the linear setting, classical results show that the…

Probability · Mathematics 2018-07-04 Yu Gu , Tomasz Komorowski , Lenya Ryzhik

Excitonic transport in static disordered one dimensional systems is studied in the presence of thermal fluctuations that are described by the Haken-Strobl-Reineker model. For short times, non-diffusive behavior is observed that can be…

Mesoscale and Nanoscale Physics · Physics 2015-05-05 Jeremy M. Moix , Michael Khasin , Jianshu Cao

The transport of single-phase fluid mixtures in porous media is described by cross-diffusion equations for the mass densities. The equations are obtained in a thermodynamic consistent way from mass balance, Darcy's law, and the van der…

Analysis of PDEs · Mathematics 2016-12-14 Ansgar Jüngel , Jiří Mikyška , Nicola Zamponi

This is an attempt to address diffusion phenomena from the point of view of information theory. We imagine a regular hamiltonian system under the random perturbation of thermal (molecular) noise and chaotic instability. The irregularity of…

Statistical Mechanics · Physics 2007-05-23 Qiuping A. Wang

In this paper, we introduce a new method of sampling from transition densities of diffusion processes including those unknown in closed forms by solving a partial differential equation satisfied by the quotient of transition densities. We…

Probability · Mathematics 2020-12-04 Yasin Kikabi , Juma Kasozi

We present a simple and systematic procedure to determine the effective dynamics of a Brownian particle coupled to a rapidly fluctuating correlated medium, modeled as a scalar Gaussian field, under spatial confinement. The method allows us,…

Statistical Mechanics · Physics 2023-01-02 Davide Venturelli , Markus Gross

We outline a reduction scheme for a class of Brownian dynamics which leads to meaningful corrections to the Smoluchowski equation in the overdamped regime. The mobility coefficient of the reduced dynamics is obtained by exploiting the…

Statistical Mechanics · Physics 2022-05-19 Matteo Colangeli , Adrian Muntean

We present a perturbation theory by extending a prescription due to Feynman for computing the probability density function for the random flight motion. The method can be applied to a wide variety of otherwise difficult circumstances. The…

Classical Physics · Physics 2007-05-23 S. Tim Hatamian

The Active Brownian Particle (ABP) model exemplifies a wide class of active matter particles. In this work, we demonstrate how this model can be cast into a field theory in both two and three dimensions. Our aim is manifold: we wish both to…

Soft Condensed Matter · Physics 2022-12-26 Ziluo Zhang , Lili Fehértói-Nagy , Maria Polackova , Gunnar Pruessner

Motivated by the phenomenon of transport barriers in fusion plasma devices, we write a mathematical model of heat dispersion in a turbulent fluid with a transport barrier, properly idealized; in a scaling limit of the turbulence model with…

Probability · Mathematics 2025-10-21 Olga Aryasova , Franco Flandoli , Andrey Pilipenko

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