ON WEYLS THEOREM FOR QUASI-CLASS A OPERATORS

Title & Authors
ON WEYLS THEOREM FOR QUASI-CLASS A OPERATORS
Duggal Bhagwati P.; Jeon, In-Ho; Kim, In-Hyoun;

Abstract
Let T be a bounded linear operator on a complex infinite dimensional Hilbert space $\small{\scr{H}}$. We say that T is a quasi-class A operator if $\small{T^*\|T^2\|T{\geq}T^*\|T\|^2T}$. In this paper we prove that if T is a quasi-class A operator and f is a function analytic on a neigh-borhood or the spectrum or T, then f(T) satisfies Weyls theorem and f($\small{T^*}$) satisfies a-Weyls theorem.
Keywords
quasi-class A operators;Weyls theorem;a-Weyls theorem;a-Browder theorem;
Language
English
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