On the Covariance of Moore-Penrose Inverses in Rings with Involution

الملخص EN

We consider the so-called covariance set of Moore-Penrose inverses in rings with an involution.

We deduce some new results concerning covariance set.

We will show that if a is a regular element in a C ∗ -algebra, then the covariance set of a is closed in the set of invertible elements (with relative topology) of C ∗ -algebra and is a cone in the C ∗ -algebra.