Rotations and Tangent Processes on Wiener Space

The paper considers (a) Representations of measure preserving transformations (``rotations'') on Wiener space, and (b) The stochastic calculus of variations induced by parameterized rotations \{T_\theta w, 0 \le \theta \le \eps\}: ``Directional derivatives'' $(dF(T_\theta w)/d \theta)_{\theta=0}$, ``vector fields'' or ``tangent processes'' $(dT_\theta w /d\theta)_{\theta=0}$ and flows of rotations.Comment: 29 page

The Sard Inequality on Wiener Space

AbstractLetT(w)=w+u(w) be a Cameron–Martin perturbation of the identity. The formal infinite dimensional extension of the Sard inequality,μ(TA)⩽∫A|Lambda;|dμ,is shown to hold and applications to absolute continuity on Wiener space are presented