The time-dependent solution of the periodically forced Fokker-Planck equation is determined, following an iteration procedure. The mixing property of the system is verified. The enhancements of the autocorrelation and the signal-to-noise ratio are distinguished and localized, in different noise strength regions. The conditions for the validity of the adiabatic approximation and the way to systematically improve the adiabatic result are clarified.

• Received 9 January 1990

DOI:https://doi.org/10.1103/PhysRevA.42.2030