Stochastic theory of phase transition in multiple steady state chemical system: Nucleation

We study on a simple reaction-diffusion system the role of stochastic fluctuation in first order type transition between two stable steady states. We focus especially on the large fluctuations in a small spatial region that give rise to nucleation. The theory of nucleation developed is based on a birth-and-death type master equation. The result is different from the Langevin approach, and the physical basis of the difference is discussed.