DYNAMICAL ORDERING - APPLICATIONS TO FOKKER-PLANCK EQUATIONS

A transformation of the linear second-order Fokker-Planck equations oc curring in quantum optics is presented which overcomes difficulties co nnected with negative definiteness of the diffusion matrices. This tra nsformation is based on a dynamical ordering of quantum quasiprobabili ty distribution functions. The ordering depends on the parameters of t he dynamical problem under consideration. An algorithm leading to exac t solutions of the dynamically ordered Fokker-Planck equations with ar bitrary initial conditions is given, and simple criteria, how to recog nize squeezed light in arbitrary ordering, are presented. The problem of Fokker-Planck equations with time-dependent diffusion is also inves tigated.