Résumé
We study the asymptotic behavior of multiscale stochastic gene networks using
weak limits of Markov jump processes. Depending on the time and concentration
scales of the system we distinguish four types of limits: continuous piecewise
deterministic processes (PDP) with switching, PDP with jumps in the continuous
variables, averaged PDP, and PDP with singular switching. We justify rigorously
the convergence for the four types of limits. The convergence results can be
used to simplify the stochastic dynamics of gene network models arising in
molecular biology.