Generalized Drazin invertibility of operator matrices

摘要

Let A. L(X) and B. L(Y), where X and Y are Banach or separable Hilbert spaces, and let MC be an operator acting on X. Y given by MC = A C 0 B . We investigate the set C. L(Y, X) sgD(MC), where sgD(MC) is the generalized Drazin spectrum of MC.