Rare Event Monte Carlo and Importance Sampling
Suppose that in the analysis of some system, the value of a probability or expected value that is largely determined by one or a few events is important. Examples include the data loss in a communication network; depletion of capital reserves in a model for insurance; motion between metastable states in a chemical reaction network; and exceedance of a regulatory threshold in a model for pollution in a waterway. In previous chapters we have described how large deviation theory gives approximations for such quantities. The approximations take the form of logarithmic asymptotics, i.e., exponential decay rates.