Mesoscopic nonequilibrium thermodynamics; irreversible processes and fluctuations

A theory of mesoscopic nonequilibrium thermodynamics is proposed, incorpora ting into thermodynamics of irreversible processes the treatment of fluctua tions of macroscopic variables, as well as of fluctuations of their distrib ution functions. The theory developed leads in a simple way to the multivar iate Fokker-Planck equations obeyed by these fluctuations. The formalism de veloped also permits to derive Fokker-Planck-Langevin equations for the dis tribution function of the macroscopic variables. A brief discussion is give n of the properties of the random force terms in these equations. (C) 1999 Elsevier Science B.V. All rights reserved.