Stochastic escape processes from a non-symmetric potential normal form III:: extended explosive systems

The stochastic dynamics to reach the hot attractor of an explosive extended system is analytically Studied by using a previously reported scheme: The stochastic path perturbation approach (Caceres M O, Budde C E and Sibona G J 1995 J. Phys. A: Math. Gen. 28 3877). A perturbation theory in the small noise parameter is introduced to analyse the random escape of the stochastic held from criticality. The anomalous fluctuations of the order parameter (the temperature profile) are calculated analytically using an instanton-like approximation. Emphasis is placed on a thermal non-homogeneous explosion in order to exemplify a system undergoing hysteresis in a first-order non-equilibrium phase transition. Concerning the stochastic propagation of the flame front we have carried out Monte Carlo simulations showing good agreement with our theoretical predictions.