title: Fluctuation-dissipation relation for nonlinear Langevin equations.
abstract: It is shown that the fluctuation-dissipation theorem is satisfied by the solutions of a general set of nonlinear Langevin equations with a quadratic free-energy functional (constant susceptibility) and field-dependent kinetic coefficients, provided the kinetic coefficients satisfy the Onsager reciprocal relations for the irreversible terms and the antisymmetry relations for the reversible terms. The analysis employs a perturbation expansion of the nonlinear terms, and a functional integral calculation of the correlation and response functions, and it is shown that the fluctuation-dissipation relation is satisfied at each order in the expansion.
authors: Department of Chemical Engineering, Indian Institute of Science, Bangalore 560 012, India. kumaran@chemeng.iisc.ernet.in
authors: V
authors: V
authors: Kumaran