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On the generalized Drazin inverse and generalized resolvent. (English) Zbl 1079.47501
Summary: We investigate the generalized Drazin inverse and the generalized resolvent in Banach algebras. The Laurent expansion of the generalized resolvent in Banach algebras is introduced. The Drazin index of a Banach algebra element is characterized in terms of the existence of a particularly chosen limit process. As an application, the computing of the Moore-Penrose inverse in C * -algebras is considered. We investigate the generalized Drazin inverse as an outer inverse with prescribed range and kernel. Also, 2×2 operator matrices are considered. As corollaries, we get some well-known results.

MSC:
47A05General theory of linear operators
47A10Spectrum and resolvent of linear operators
46L05General theory of C * -algebras