Towards a nonlinear theory of fluctuations of macroscopic quantities (thermal perturbations)

Abstract

Nonlinear fluctuation-dissipation relations (FDR), the validity of which was strictly proved for dynamic perturbations, are extended to include a wide class of physical quantities, such as temperature, entropy and chemical potential, that have a special statistical origin. The nonlinear Langevin equations have been constructed and the correlation functions for the fluctuation sources in these equations have been found.