An. Borodin et Mi. Freidlin, FAST OSCILLATING RANDOM PERTURBATIONS OF DYNAMICAL-SYSTEMS WITH CONSERVATION-LAWS, Annales de l'I.H.P. Probabilites et statistiques, 31(3), 1995, pp. 485-525
We consider fast oscillating random perturbations of dynamical systems
with first integrals. We prove that if the dynamical system is ergodi
c in the subset of the phase space where the first integrals are const
ants, then the evolution of the first integrals in a proper time scale
is described by a diffusion process.