A stochastic model is proposed to take into account the effect of a weak external field associated to diffusion, a discrete Master Equation is written down for the spatial distribution of particles. Approximate solutions are found for the first two cumulants, and applied to an example of...

We present a stochastic study of a polymerization reaction model. Using the WKB approximation and the method of factorial cumulants it is shown that the relaxation time of the second factorial cumulant is half the macroscopic relaxation time. Furthermore the system exhibits a globally...