Fritz Gesztesy, Mark Malamud, Marius Mitrea, and Serguei Naboko Generalized Polar Decompositions for Closed Operators in Hilbert Spaces and Some Applications (95K, LaTeX) ABSTRACT. We study generalized polar decompositions of densely defined, closed linear operators in Hilbert spaces and provide some applications to relatively (form) bounded and relatively (form) compact perturbations of self-adjoint, normal, and m-sectorial operators.