We show that a Brownian motion can be derived for a particle coupled to a bath with a finite number of chaotic degrees of freedom, using no thermodynamics assumptions. We point out that although diffusion is easily derived in terms of the unperturbed bath via the central limit theorem, friction is obtained only when the coupling between particle of interest and bath is considered. The only assumption made is that the bath should respond linearly (in statistical sense) to a weak external perturbation. We prove that the calculation of the friction can be traced back to the bath susceptibility.

THE LINEAR-RESPONSE APPROACH TO THE FOKKER-PLANCK EQUATION .1. THEORY

MANNELLA, RICCARDO;
1994

Abstract

We show that a Brownian motion can be derived for a particle coupled to a bath with a finite number of chaotic degrees of freedom, using no thermodynamics assumptions. We point out that although diffusion is easily derived in terms of the unperturbed bath via the central limit theorem, friction is obtained only when the coupling between particle of interest and bath is considered. The only assumption made is that the bath should respond linearly (in statistical sense) to a weak external perturbation. We prove that the calculation of the friction can be traced back to the bath susceptibility.
Bianucci, M; Mannella, Riccardo; Grigolini, P; West, Bj
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11568/22945
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