D S Dean et al 2004 J. Phys. A: Math. Gen. 37 10459 doi:10.1088/0305-4470/37/44/001
D S Dean1,2, I T Drummond1, R R Horgan1 and A Lefèvre3
Show affiliationsWe develop perturbation theory and physically motivated resummations of the perturbation theory for the problem of a tracer particle diffusing in a random medium. The random medium contains point scatterers of density ρ uniformly distributed throughout the material. The tracer is a Langevin particle subjected to the quenched random force generated by the scatterers. Via our perturbative analysis, we determine when the random potential can be approximated by a Gaussian random potential. We also develop a self-similar renormalization group approach based on thinning out the scatterers; this scheme is similar to that used with success for diffusion in Gaussian random potentials and agrees with known exact results. To assess the accuracy of this approximation scheme, its predictions are confronted with results obtained by numerical simulation.
05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion
02.50.-r Probability theory, stochastic processes, and statistics
Issue 44 (5 November 2004)
Received 23 July 2004
Published 20 October 2004
D S Dean et al 2004 J. Phys. A: Math. Gen. 37 10459
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