ABSTRACT
This work gives a survey of the results obtained in a series of papers [1], [5] – [17]. This survey has had as a starting point our lectures at the conference on stochastic partial differential equations in Levico (January 2000) with a continuation at the conference on stochastic analysis in Bielefeld (August 2000) and in a series of the first author’s lectures in Kyoto and Osaka in October 2000. It is our pleasure to thank G. Da Prato, M. Fukushima, N. Krylov, I. Shigekawa, and L. Tubaro.
