Weyl-Type Theorems on Banach Spaces Under Compact Perturbations

Abstract

In this paper, we study Browder-type and Weyl-type theorems for operators T+ K defined on a Banach space X, where K is (a non necessarily commuting) compact operator on X. In the last part, the theory is exemplified in the case of isometries, analytic Toeplitz operators, semi-shift operators, and weighted right shifts.