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arXiv · 1905.07768

Drift-diffusion processes from elimination of fast variables under inhomogeneous conditions

Paul E. Lammert
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Abstract

The problem of eliminating fast-relaxing variables to obtain an effective drift-diffusion process in position is solved in a uniform and straightforward way for models with velocity a function jointly of position and fast variables. A more unified view is thereby obtained of the effect of environmental inhomgeneity on the motion of a diffusing particle, in particular, whether a drift is induced, covering both passive and active particles. Infinitesimal generators (equivalently, drift-diffusion fields) for the contracted processes are worked out in detail for several models.

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Paul E. Lammert. 2019-05-19. Drift-diffusion processes from elimination of fast variables under inhomogeneous conditions. https://doi.org/10.1103/physreve.100.052103

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