Boundedness of Riesz transforms for elliptic operators on abstract Wiener spaces

Let (E,H,μ) be an abstract Wiener space and let DV :=VD, where D denotes the Malliavin derivative and V is a closed and densely defined operator from H into another Hilbert space H. Given a bounded operator B on H, coercive on the range R(V ), we consider the operators A := V ∗BV in H and A := VV∗B in H, as well as the realisations of the operators L := D∗V BDV and L := DV D∗V B in Lp(E,μ) and Lp(E,μ;H) respectively, where 1