Two Langevin equations in the Doi-Peliti formalism

Abstract

A system-size expansion method is incorporated into the DoiPeliti formalism for stochastic chemical kinetics. The basic idea of the incorporation is to introduce a new decomposition of unity associated with the so-called Cole Hopf transformation. This approach elucidates a relationship between two different Langevin equations; one is associated with a coherent-state pathintegral expression and the other describes density fluctuations. A simple reaction scheme X ⇄ X + X is investigated as an illustrative example. © 2010 IOP Publishing Ltd.