THE FOKKER-PLANCK EQUATION FOR ARBITRARY NONLINEAR NOISE

We present the Fokker-Planck equation for arbitrary nonlinear noise te rms. The white noise limit is taken as the zero correlation time limit of the Ornstein-Uhlenbeck process. The drift and diffusion coefficien ts of the Fokker-Planck equation are given by triple integrals of the fluctuations. We apply the Fokker-Planck equation to the active rotato r model with a fluctuating potential barrier which depends nonlinearly on an additive noise. We show that the nonlinearity may be transforme d into the correlation of linear noise terms. (C) 1997 Published by El sevier Science B.V.