Colored non-Gaussian noise driven open systems: Generalization of Kramers' theory with a unified approach

In this paper we have calculated escape rate from a meta stable state in the presence of both colored internal thermal and external nonthermal noises. For the internal noise we have considered usual Gaussian distribution but the external noise may be Gaussian or non-Gaussian in characteristic. The calculated rate is valid for low noise strength of non-Gaussian noise such that an effective Gaussian approximation of non-Gaussian noise wherein the higher order even cumulants of order "4" and higher are neglected. The rate expression we derived here reduces to the known results of the literature, as well as for purely external noise driven activated rate process. The latter exhibits how the rate changes if one switches from non-Gaussian to Gaussian character of the external noise. (C) 2011 American Institute of Physics. [doi:10.1063/1.3521394]