Stochastic resonance and noise at coupled phase transitions

The system of two nonlinear stochastic equations simulating 1 / f fluctuations during the interaction of nonequilibrium phase transitions in the presence of an external periodic action has been studied by numerical methods. It is shown that in the system there appears stochastic resonance, which leads to an amplification of the output periodic signal under the action of noise. andom process with a 1 / f power spectrum corresponds the maximum Gibbs–Shannon informational entropy. At stochastic resonance the informational entropy is minimum. A new behavior of a two-dimensional system at stochastic resonance has been revealed: at low frequencies of a periodic action with an increased white noise intensity the system trajectories are limited by two mutually perpendicular directions—anisotropic stochastic resonance. With a further increase in the white noise intensity in the system one can observe “ordinary” stochastic resonance, when the increasing intensity of fluctuations in the vicinity of the driving frequency is smeared in the directions.