Lowfrequency correlation functions in case of nonlinear dynamics of fluctuations
Abstract
A method is developed for calculating lowfrequency asymptotic correlation functions of basic operators “ â_{m}” which correspond to gross variables describing a nonequibliriium state of a system. We have introduced a Weyl operator, its nonequilibrium average value being considered as a quantum distribution function of gross variables. The generalized FokkerPlanck equation is then derived for the distribution function. This equation is used for obtaining a chain of equations for asymptotic correlation functions containing only Weyl operator functions of “ â_{m}”. The kinetic coefficients and selfenergy are expressed in terms of irreducible correlation functions which correspond to effects of nonlinear dynamics of fluctuations. It is shown in our approach that hydrodynamic modes may be considered as a zero order approximation. As an application of the formalism the generalized modemode coupling approximation is investigated.
 Publication:

Physica A Statistical Mechanics and its Applications
 Pub Date:
 January 1982
 DOI:
 10.1016/03784371(82)90111X
 Bibcode:
 1982PhyA..110..201M