PROBABILITY-DISTRIBUTIONS AND ESCAPE RATES FOR SYSTEMS DRIVEN BY QUASI-MONOCHROMATIC NOISE

The motion of an overdamped particle in a bistable potential U(x), dri ven by quasimonochromatic noise (high-frequency, narrow-band noise), h as been investigated by means of electronic analog simulation. The esc ape rate from one potential well to another was found to be exponentia lly small compared to the reciprocal mean first-passage time to the to p of the potential barrier. The logarithm of the quasistationary proba bility distribution was observed to fall extremely sharply at a partic ular value of x, quite close to the equilibrium position. Theory descr ibing the nonanalytic dependence of this logarithm on the bandwidth of the noise is presented and shown to be in good agreement with experim ent. Data are also presented for a symmetric monostable potential. In a certain parameter range, the quasistationary distribution is demonst rated to be independent of the form of such a potential.