Results 1 to 10 of about 92 (86)
On Subscalarity of Some 2 × 2 M‐Hyponormal Operator Matrices [PDF]
Abstract and Applied Analysis, Volume 2014, Issue 1, 2014., 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, Yisheng Song
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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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Neurogastroenterology &Motility, Volume 35, Issue 2, February 2023., 2023 Patients with gastroparesis (GP) and functional dyspepsia (FD) have similar symptoms, but the pathophysiology of symptoms remains uncertain. Results show symptoms and gastric myoelectrical responses after ingestion of solid or liquid test meals are similar and suggests GP and FD are closely related gastric neuromuscular disorders.
Kenneth L. Koch +14 more
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Emergency Medicine International, Volume 2023, Issue 1, 2023., 2023 This study was developed to explore the correlation between diabetic nephropathy (DN) and abnormal serum thyroid hormone (TH) levels in patients, which can provide a reference for disease prevention and control in patients with DN. DN is the most serious complication of diabetes. The mortality rate of diabetic patients with DN is approximately 30 times
Zhiqiu Liu, Yuvaraja Teekaraman
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(α, β)‐Normal Operators in Several Variables
Mathematical Problems in Engineering, Volume 2022, Issue 1, 2022., 2022 We consider an extension of the concept of (α, β)‐normal operators in single variable operator to tuples of operators, similar to those extensions of the concepts of normality to joint normality, hyponormality to joint hyponormality, and quasi‐hyponormality to joint quasi‐hyponormality.
Sid Ahmed Ould Ahmed Mahmoud +3 more
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Spectral Radius Formulas Involving Generalized Aluthge Transform
Journal of Function Spaces, Volume 2022, Issue 1, 2022., 2022 In this paper, we aim to develop formulas of spectral radius for an operator S in terms of generalized Aluthge transform, numerical radius, iterated generalized Aluthge transform, and asymptotic behavior of powers of S. These formulas generalize some of the formulas of spectral radius existing in literature.
Zhiqiang Zhang +5 more
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Subnormality of Powers of Multivariable Weighted Shifts
Journal of Function Spaces, Volume 2020, Issue 1, 2020., 2020 Given a pair T ≡ (T1, T2) of commuting subnormal Hilbert space operators, the Lifting Problem for Commuting Subnormals (LPCS) asks for necessary and sufficient conditions for the existence of a commuting pair N ≡ (N1, N2) of normal extensions of T1 and T2; in other words, T is a subnormal pair.
Sang Hoon Lee +3 more
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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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Hyponormality on a Weighted Bergman Space
Journal of Function Spaces, Volume 2020, Issue 1, 2020., 2020 A bounded Hilbert space operator T is hyponormal if T∗T − TT∗ is a positive operator. We consider the hyponormality of Toeplitz operators on a weighted Bergman space. We find a necessary condition for hyponormality in the case of a symbol of the form f+g¯ where f and g are bounded analytic functions on the unit disk.
Houcine Sadraoui +4 more
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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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