Transition semigroups for stochastic semilinear equations on Hilbert spaces
A large class of stochastic semilinear equations with measurable nonlinear term on a Hilbert space H is considered. Assuming the corresponding nonsymmetric Ornstein-Uhlenbeck process has an invariant measure μ, we prove in the spaces the existence of a transition semigroup for the equations. Sufficient conditions are provided for hyperboundedness of and for the Log Sobolev Inequality to hold; and in the case of a bounded nonlinear term, sufficient and necessary conditions are obtained. We...