In this paper, the variations of both subunitary polar factors and Hermitian positive semidefinite polar factors in the polar decomposition are studied. New perturbation bounds of both polar factors are given without the restriction that A and its perturbed matrix à have the same rank. These improve recent results. [ABSTRACT FROM AUTHOR]
In this note, we present an explicit formula for perturbations of an outer inverse under certain conditions, which extends previous results. [ABSTRACT FROM AUTHOR]