We present a general setting to investigate U_fin-cocycle superrigidity for
Gaussian actions in terms of closable derivations on von Neumann algebras. In
this setting we give new proofs to some U_fin-cocycle superrigidity results of
S. Popa and we produce new examples of this phenomenon. We also use a result of
K. Schmidt to give a necessary cohomological condition on a group
representation in order for the resulting Gaussian action to be U_fin-cocycle
superrigid.