Effects of the Noises' Statistics and Spectrum on Noise-Induced Phase Transitions

摘要

The study of the effect of the noises' statistics and spectrum on second-order, purely noise-induced phase transition (NIPT) is of wide interest: It is simplified if the noises are dynamically generated by means of stochastic differential equations driven by white noises, a well known case being that of Ornstein-Uhlenbeck noises with a self-correlation time tau whose effect on the NIPT phase diagram has been studied some time ago. Another case is when the stationary pdf is a (colored) q-Gaussian which, being a fat-tail distribution for q > 1 and a compact-support one for q < 1, allows for a controlled study of the effects of the departure from Gaussian statistics. As done with stochastic resonance and other phenomena, we exploit this tool to study--within a simple meanfield approximation-the combined effect on NIPT of the noises' statistics and spectrum. Even for relatively small tau, it is shown that whereas for fat-tail noise distributions counteract the effect of self-correlation, compact-support ones enhance it.