Martin Hairer Exponential Mixing for a Stochastic PDE Driven by Denerate Noise (137K, PostScript) ABSTRACT. We study stochastic partial differential equations of the reaction-diffusion type. We show that, even if the forcing is very degenerate (i.e. has not full rank), one has exponential convergence towards the invariant measure. The convergence takes place in the topology induced by a weighted variation norm and uses a kind of (uniform) Doeblin condition.