Several properties on class A including p-hyponormal and log-hyponormal operators
نویسندگان
چکیده
منابع مشابه
ON p-HYPONORMAL OPERATORS
In this paper we show that p-hyponormal operators with 0 / ∈ σ(|T | 1 2 r ) are subscalar. As a corollary, we get that such operators with rich spectra have non-trivial invariant subspaces.
متن کاملEXTENSIONS OF THE RESULTS ON POWERS OFp-HYPONORMAL AND log-HYPONORMAL OPERATORS
Firstly, we will show the following extension of the results on powers of p-hyponormal and log-hyponormal operators: let n andm be positive integers, if T is p-hyponormal for p ∈ (0,2], then: (i) in case m ≥ p, (Tn+mTn+m)(n+p)/(n+m) ≥ (TnTn)(n+p)/n and (TnTn ∗ )(n+p)/n ≥ (Tn+mTn+m)(n+p)/(n+m) hold, (ii) in case m < p, Tn+mTn+m ≥ (Tn ∗ Tn)(n+m)/n and (TnTn ∗ )(n+m)/n ≥ Tn+mTn+m hold. Secondly, w...
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A survey of the theory of k-hyponormal operators starts with the construction of a polynomially hyponormal operator which is not subnormal. This is achieved via a natural dictionary between positive functionals on specific convex cones of polynomials and linear bounded operators acting on a Hilbert space, with a distinguished cyclic vector. The class of unilateral weighted shifts provides an op...
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In [1] D. Harrington and R. Whitley examined several questions of seminormality for composition operators. In that article they raise the question of finding a measure theoretic characterization of hyponormality for composition operators. In this article we establish criteria for hyponormality for weighted composition operators. By restricting attention to the case of weight function equal to 1...
متن کاملOn Commutators of Isometries and Hyponormal Operators
A sufficient condition is obtained for two isometries to be unitarily equivalent. Also, a new class of M-hyponormal operator is constructed
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ژورنال
عنوان ژورنال: Mathematical Inequalities & Applications
سال: 1999
ISSN: 1331-4343
DOI: 10.7153/mia-02-48