Equations of motion for the parameters of a weakly nonequilibrium system

The nonequilibrium statistical operator method is used to show that in general form equations of motion for the parameters of a weakly nonequilibrium system can be expressed in terms of their equilibrium retarded Green's functions. The characteristic frequencies and spectrum of relaxation times are determined by the poles of these functions. The relationship between these equations and the analogous equations in the Mort scheme is established.