STOCHASTIC RESONANT MEDIA - SIGNAL-TO-NOISE RATIO FOR THE ACTIVATOR-INHIBITOR SYSTEM THROUGH A QUASI-VARIATIONAL APPROACH

We have made an analytical study of the phenomenon of stochastic reson ance in a spatially extended stochastic system of the activator-inhibi tor kind. In its bistable regime, through a quasivariational approach we make an approximate evaluation of the nonequilibrium potential for this system. The latter in turn allows us to obtain the probability fo r the decay of the (extended) metastable states and through it the sig nal-to-noise ratio within the framework of a two-state description. Th e analytical results show that this ratio increases with the. activato r's diffusivity, whereas it exhibits nonmonotonic behavior against var iation of the coupling between both fields.