ON QUASI-CLASS A OPERATORS
Let QA denote the class of bounded linear Hilbert space operators T which satisfy the operator inequality
T^* |T^2| T ≥ T^* |T|^2 T.
Let f be an analytic function defined on an open neighbourhood U of σ(T) such that f is non–constant on the connected components of U. We generalize a theorem of Sheth  to f(T) ∈ QA.
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ISSN: 1976-8605 (Print), 2288-1433 (Online)
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