Master equation and molecular dynamics simulations of excitability in a model chemical system

We study the influence of internal fluctuations on a simple but realistic model of a chemical system in an excitable regime. Numerical simulations of the master equation are compared with results of molecular dynamics simulations. We show that internal fluctuations are able to excite the system, which is initially at a stable stationary state. The dependence of escape time on the system's volume is studied. We observe that correlations of fluctuations in concentrations do not depend on the volume and the results of both simulation methods are in excellent agreement.