Eur. Phys. J. B (2016) 89: 79
https://doi.org/10.1140/epjb/e2016-60963-3

Regular Article

Brownian motion on random dynamical landscapes

¹ Departament d’Estructura i Constituents de la MatèriaFacultat de Física, Universitat de Barcelona, Diagonal 647, 08028 Barcelona, Spain
² Department of Chemistry and Biochemistry and BioCircuits Institute, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, USA

^a e-mail: sune@ecm.ub.edu

Received: 15 December 2015
Received in final form: 4 February 2016
Published online: 23 March 2016

Abstract

We present a study of overdamped Brownian particles moving on a random landscape of dynamic and deformable obstacles (spatio-temporal disorder). The obstacles move randomly, assemble, and dissociate following their own dynamics. This landscape may account for a soft matter or liquid environment in which large obstacles, such as macromolecules and organelles in the cytoplasm of a living cell, or colloids or polymers in a liquid, move slowly leading to crowding effects. This representation also constitutes a novel approach to the macroscopic dynamics exhibited by active matter media. We present numerical results on the transport and diffusion properties of Brownian particles under this disorder biased by a constant external force. The landscape dynamics are characterized by a Gaussian spatio-temporal correlation, with fixed time and spatial scales, and controlled obstacle concentrations.