Results 21 to 30 of about 92 (86)
The Near Subnormal Weighted Shift and Recursiveness
International Journal of Analysis, Volume 2013, Issue 1, 2013., 2013 We aim at studying the near subnormality of the unilateral weighted shifts, whose moment sequences are defined by linear recursive relations of finite order. Using the basic properties of recursive sequences, we provide a natural necessary condition, that ensure the near subnormality of this important class of weighted shifs.
R. Ben Taher, M. Rachidi, Chuanxi Qian
wiley +1 more source
Journal of Mathematical InequalitiesSummary: A bounded linear operator \(T: \mathscr{H}\rightarrow\mathscr{H}\) is a \(C\)-\textit{hyponormal} operator if \(T^\ast T - CTT^\ast C \geqslant 0\) for a conjugation \(C\) on \(\mathscr{H}\). In this paper, we study properties of \(C\)-hyponormal operators. Especially, we prove that for \(\mathscr{M}\in\mathrm{Lat}(T)\) and a conjugation \(C =
Ko, Eungil, Lee, Ji Eun, Lee, Mee-Jung
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Similarity of C1: Operators and the Hyperinvariant Subspace Problem
Journal of Mathematics, Volume 2024, Issue 1, 2024.In the present paper, we first show that the existence of the solutions of the operator equation S∗XT = X is related to the similarity of operators of class C1., and then we give a sufficient condition for the existence of nontrivial hyperinvariant subspaces. These subspaces are the closure of ranφ(T) for some singular inner functions φ.
Abdelkader Segres +3 more
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More on (α, β)‐Normal Operators in Hilbert Spaces
Abstract and Applied Analysis, Volume 2012, Issue 1, 2012., 2012 We study some properties of (α, β)‐normal operators and we present various inequalities between the operator norm and the numerical radius of (α, β)‐normal operators on Banach algebra ℬ(ℋ) of all bounded linear operators T : ℋ → ℋ, where ℋ is Hilbert space.
Rasoul Eskandari +3 more
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The Spectra of Unbounded Hyponormal Operators [PDF]
Proceedings of the American Mathematical Society, 1972 A bounded operator T T on a Hilbert space is said to be completely hyponormal if
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On hyponormal operators in Krein spaces [PDF]
Archivum Mathematicum, 2019 Summary: In this paper the hyponormal operators on Krein spaces are introduced. We state conditions for the hyponormality of bounded operators focusing, in particular, on those operators \(T\) for which there exists a fundamental decomposition \(\mathcal{K}=\mathcal{K}^+\oplus\mathcal{K}^-\) of the Krein space \(\mathcal{K}\) with \(\mathcal{K}^+\) and
Esmeral, Kevin +3 more
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Orbits of hyponormal operators.
Michigan Mathematical Journal, 1997 A bounded linear operator \(A\) on the Hilbert space \(H\) is hypercyclic if there is a vector \(x\in H\) such that \[ \text{Orb}(A,x)=\{A^nx: n=0,1,2,\cdots\} \] is dense in \(H\). In this case we say that \(x\) is a hypercyclic vector for \(A\). We say that \(A\) is supercyclic if there is a vector \(x\in H\) such that \[ \{\lambda A^nx:\lambda\in ...
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Nonlinear Analysis: Algorithm, Convergence, and Applications 2014
, 2014 Abstract and Applied Analysis, Volume 2014, Issue 1, 2014.
Yisheng Song +4 more
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Hyponormal operators quasisimilar to an isometry [PDF]
Transactions of the American Mathematical Society, 1985 An expression for the multiplicity of an arbitrary contraction is presented. It is in terms of the isometries which can be densely intertwined to the given contraction. This is then used to obtain a generalization of a result of Sz.-Nagy and Foiaş concerning the existence of a
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On p-quasi-hyponormal operators
Linear Algebra and its Applications, 2007 For an infinite-dimensional Hilbert space \(H\), let \(B(H)\) denote the algebra of all bounded linear operators on \(H\).
Duggal, B.P., Jeon, In Ho
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