Invariant measures for stochastic heat equations with unbounded coefficients

The paper deals with the Cauchy problem in Rd of a stochastic heat equation ∂u/∂t=λΔu+f(u)+σ(u)Ẇ. The locally lipschitz drift coefficient f can have polynomial growth while the diffusion coefficient σ is supposed to be lipschitz but not necessarily bounded. Of course, for the existence of a solution alone, a certain dissipativity of f is needed. Applying the comparison method, a condition on the strength of this dissipativity is derived even ensuring the existence of an invariant measure.