Results 11 to 20 of about 137 (130)
Hyponormality on a Weighted Bergman Space
Journal of Function Spaces, 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.
Houcine Sadraoui +3 more
doaj +2 more sources
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
wiley +1 more source
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
wiley +1 more source
(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
wiley +1 more source
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
wiley +1 more source
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
wiley +1 more source
A Note on Hyponormal Operators [PDF]
Proceedings of the American Mathematical Society, 1975 A short, elementary proof that a hyponormal operator with a compact imaginary part is normal.
openaire +2 more sources
Some remarks on the invariant subspace problem for hyponormal operators
International Journal of Mathematics and Mathematical Sciences, 2001 We make some remarks concerning the invariant subspace problem for hyponormal operators. In particular, we bring together various hypotheses that must hold for a hyponormal operator without nontrivial invariant subspaces, and we discuss the existence of ...
Vasile Lauric
doaj +1 more source
Commuting hyponormal operators [PDF]
Pacific Journal of Mathematics, 1980 Introduction* Let T be a completely nonunitary contraction on Hubert space such that 1 — T*T has closed range. There exists a power series B(z) = ΣBnzn with operator coefficients which converges and is bounded by one in the unit disk such that T is unitarily equivalent to the difference-quotient transformation in the de Branges-Rovnyak space 3f(B) [1 ...
openaire +2 more sources
A note on 𝑝-hyponormal operators [PDF]
Proceedings of the American Mathematical Society, 1997 Let T T be a p
Cao, Xiaohong, Guo, Maozheng, Meng, Bin
openaire +5 more sources