Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/18824
Title: Phenomenological approach to nonlinear Langevin equations
Author: Bonet i Avalos, Josep
Pagonabarraga Mora, Ignacio
Keywords: Equacions diferencials estocàstiques
Mecànica estadística
Equació de Fokker-Planck
Moviment brownià
Stochastic differential equations
Statistical mechanics
Fokker-Planck equation
Brownian movements
Issue Date: 1995
Publisher: The American Physical Society
Abstract: In this paper we address the problem of consistently constructing Langevin equations to describe fluctuations in nonlinear systems. Detailed balance severely restricts the choice of the random force, but we prove that this property, together with the macroscopic knowledge of the system, is not enough to determine all the properties of the random force. If the cause of the fluctuations is weakly coupled to the fluctuating variable, then the statistical properties of the random force can be completely specified. For variables odd under time reversal, microscopic reversibility and weak coupling impose symmetry relations on the variable-dependent Onsager coefficients. We then analyze the fluctuations in two cases: Brownian motion in position space and an asymmetric diode, for which the analysis based in the master equation approach is known. We find that, to the order of validity of the Langevin equation proposed here, the phenomenological theory is in agreement with the results predicted by more microscopic models
Note: Reproducció del document publicat a: http://dx.doi.org/10.1103/PhysRevE.52.5881
It is part of: Physical Review E, 1995, vol. 52, núm. 6, p. 5881-5892
URI: http://hdl.handle.net/2445/18824
ISSN: 1063-651X
Appears in Collections:Articles publicats en revistes (Física de la Matèria Condensada)

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