Results 1 to 10 of about 137 (130)
On Subscalarity of Some 2 × 2 M-Hyponormal Operator Matrices [PDF]
Abstract and Applied Analysis, 2014 We provide some conditions for 2×2 operator matrices whose diagonal entries are M-hyponormal operators to be subscalar. As a consequence, we obtain that Weyl type theorem holds for such operator matrices.
Fei Zuo, Junli Shen
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KARAKTERISTIK OPERATOR PARANORMAL- * QUASI
Jurnal Lebesgue, 2022 Given Hilbert space H over the fields of . This study aimed to investigate the paranormal- * quasi operators and their properties in Hilbert space.
Gunawan Gunawan, Erni Widiyastuti
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On powers of class A(k) operators including p-hyponormal and log-hyponormal operators [PDF]
Mathematical Inequalities & Applications, 2000 Recently, the class of operators known as \(p\)-hyponormal and log-hyponormal are intensively studied by many authors using Furuta inequalities. In this article the author introduces the classes \(A(k)\) and \(A(s,t)\) of operators each of them containing the classes of \(p\)-hyponormal and log-hyponormal operators.
Jeon, I. H., Tanahashi, K., Uchiyama, A.
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Hyponormal differential operators with discrete spectrum [PDF]
Opuscula Mathematica, 2010 In this work, we first describe all the maximal hyponormal extensions of a minimal operator generated by a linear differential-operator expression of the first-order in the Hilbert space of vector-functions in a finite interval.
Zameddin I. Ismailov, Erdal Unluyol
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On 𝑝-hyponormal operators [PDF]
Proceedings of the American Mathematical Society, 1999 In this paper we show that p p -hyponormal operators with
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مجلة بغداد للعلوم, 2010 In this paper, we introduce a class of operators on a Hilbert space namely quasi-posinormal operators that contain properly the classes of normal operator, hyponormal operators, M–hyponormal operators, dominant operators and posinormal operators .
Baghdad Science Journal
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A Note on the Range of the Operator 𝑋↦𝑇𝑋−𝑋𝑇 Defined on 𝒞2(ℋ)
International Journal of Mathematics and Mathematical Sciences, 2009 We show how a proof of J. Stampfli can be extended to prove that the operator 𝑋↦𝑇𝑋−𝑋𝑇 defined on the Hilbert-Schmidt class, when 𝑇 is an 𝑀-hyponormal, 𝑝-hyponormal, or log-hyponormal operator, has a closed range if and only if 𝜎(𝑇) is finite.
Vasile Lauric
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Fuglede–Putnam type theorems for (p,k) $(p,k)$-quasihyponormal operators via hyponormal operators
Journal of Inequalities and Applications, 2019 For Hilbert space operators S, X, and T, (S,X,T)∈FP $(S,X,T)\in FP$ means Fuglede–Putnam theorem holds for triplet (S,X,T) $(S,X,T)$, that is, SX=XT $SX=XT$ ensures S∗X=XT∗ $S^{\ast }X=XT^{\ast }$. Similarly, (S,T)∈FP $(S,T)\in FP$ means (S,X,T)∈FP $(S,X,
Jiang-Tao Yuan, Cai-Hong Wang
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Toeplitz and slant Toeplitz operators on the polydisk [PDF]
Arab Journal of Mathematical Sciences, 2021 For n ≥ 1, let Dn be the polydisk in ℂn, and let Tn be the n-torus. L2(Tn) denotes the space of Lebesgue square integrable functions on Tn. In this paper we define slant Toeplitz operators on L2(Tn).
Munmun Hazarika, Sougata Marik
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On unbounded hyponormal operators III [PDF]
Studia Mathematica, 1992 Let \(T\) be a densely defined operator on a complex Hilbert space. Then \(T\) is called hyponormal, if \(D(T)\subseteq D(T^*)\) and \(\| T^* x\|\leq \| Tx\|\), \(\forall x\in D(T)\). This extension of the concept of hyponormal operators to the case of unbounded operators was given by the author in a previous publication (part I), where he studied some
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