Brownian motion in dynamically disordered media

摘要: The motion of Brownian test particles in a model random potential with time dependent correlations is investigated using four methods: renormalized perturbation, perturbation Martin, Siggia, and Rose functional formalism (MSR), the Edwards variational method on MSR functional, renormalization group function. disorder averaged one-particle propagators determined by expansion are identical to second possibly higher order, two-particle these methods at first order. propagator expansions but second-order analogue has more complex expression, which reduces expression additional higher-order terms. diffusion constant calculated from used determine effects particles. Generally, rate decreases strength increases temporal decay rate. two competing mechanisms result an enhancement for weak potentials fast fluctuations. system exhibits that inherently non-Gaussian indicate clustering behavior. also simple one-loop calculation. In static limit, recovers results Deem Chandler [M.W. D. Chandler, J. Stat. Phys. 76, 911 (1994)].