报告 人：EtiennePardoux教授 (法国Aix-Marseille大学)
报告题目：Large deviations in epidemics models
As we will show, the usual ODE models forepidemies are LLN limits (as the population size tends to infinity) of Poissondriven SDE models. This means that the "original" stochastic modelis, in the case of large population, asmall random perturbation of the ODE model. Suppose an endemic situation is alocally stable equilibrium of the deterministic model. Then the theory ofWentzell and Freidlin allows us to predict the time it will take for the randomperturbations to drive the system to the extinction of the epidemic. We shallpresent recent joint work with P. Kratz, B. Samegni-Kepgnou ad B.Kouegou-Kamen, which give precise mathematical results for that problem.