Diffusion process in a deterministically forced flow

Abstract

We analyze circumstances under which the microscopic dynamics of particles which are driven by a forced, gradient-type flow can be consistently interpreted as a Markovian diffusion process. Special attention is paid to discriminating between forces that are presumed to act selectively upon diffusing particles, while leaving the random medium statistically at rest (Smoluchowski diffusion processes), and those perturbing the random medium itself and thus creating the nontrivial flows. We focus on the deterministic "stirring" scenarios.