Isolated point of spectrum of p-quasihyponormal operators
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چکیده
Let T ∈ B(H) be a bounded linear operator on a complex Hilbert space H. Let λ0 be an isolated point of σ(T ) and let E = 1 2 i ∫ |λ−λ0|=r (λ− T )−1 dλ be the Riesz idempotent for λ0. In this paper, we prove that if T is a p-quasihyponormal operator with 0 < p 1 and λ0 / = 0, then E is self-adjoint and EH = ker(T − λ0) = ker(T − λ0) ∗. © 2002 Elsevier Science Inc. All rights reserved. AMS classification: 47A10; 47B20
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تاریخ انتشار 2001