Results 21 to 30 of about 137 (130)
Hyponormality of Toeplitz operators with non-harmonic symbols on the Bergman spaces
Journal of Inequalities and Applications, 2021 In this paper, we present some necessary and sufficient conditions for the hyponormality of Toeplitz operator T φ $T_{\varphi }$ on the Bergman space A 2 ( D ) $A^{2}(\mathbb{D})$ with non-harmonic symbols under certain assumptions.
Sumin Kim, Jongrak Lee
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Boundedly Spaced Subsequences and Weak Dynamics
Journal of Function Spaces, Volume 2018, Issue 1, 2018., 2018 Weak supercyclicity is related to weak stability, which leads to the question that asks whether every weakly supercyclic power bounded operator is weakly stable. This is approached here by investigating weak l‐sequential supercyclicity for Hilbert‐space contractions through Nagy–Foliaş–Langer decomposition, thus reducing the problem to the quest of ...
C. S. Kubrusly +2 more
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Absolute continuity and hyponormal operators
International Journal of Mathematics and Mathematical Sciences, 1981 Let T be a completely hyponormal operator, with the rectangular representation T=A+iB, on a separable Hilbert space. If 0 is not an eigenvalue of T* then T also has a polar factorization T=UP, with U unitary. It is known that A,B and U are all absolutely
C. R. Putnam
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On Certain Aspects of the Multidimensional S‐Spectral Theory
Mathematical Problems in Engineering, Volume 2014, Issue 1, 2014., 2014 This paper has two parts. The first one provides the preliminary notions introducing certain general concepts, in order to study, in the second part, the properties of some operator systems which admit spectral residual decompositions, S‐decomposable, S‐spectral, and AS‐scalar systems, and so forth. The results obtained by Frunză, 1975, are generalized,
Cristina Serbanescu +2 more
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On quasi-similarity and ω-hyponormal operators [PDF]
Opuscula Mathematica, 2007 In this paper, it is shown that a Putnam-Fuglede type commutativity theorem holds for \(\omega\)-hyponormal operators, the normal parts of quasi-similar \(\omega\)-hyponormal operators are unitarily equivalent and a \(\omega\)-hyponormal spectral ...
Mourice Ouma Otieno
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Isomorphic Operators and Functional Equations for the Skew‐Circulant Algebra
Abstract and Applied Analysis, Volume 2014, Issue 1, 2014., 2014 The skew‐circulant matrix has been used in solving ordinary differential equations. We prove that the set of skew‐circulants with complex entries has an idempotent basis. On that basis, a skew‐cyclic group of automorphisms and functional equations on the skew‐circulant algebra is introduced.
Zhaolin Jiang +3 more
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Journal of Applied Science and EngineeringThis study aims to investigate the realm of operator theory related to Fuzzy Soft Theory. Based on fuzzy soft Hilbert spaces, a novel formula of fuzzy soft quasi-hyponormal operator via a technique of fuzzy soft Drazin inverse named the fuzzy soft n ...
Salim Dawood Mohsen, Zaid Rajih Hamza
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On Perturbation of Fuzzy Soft κ Quasi Hyponormal Operator Generator via A Special Class of Operators
مجلة بغداد للعلومHilbert space has been improved by building on a fuzzy soft vector space. It is named the fuzzy soft Hilbert space. This space has been crucial to the development of functional analysis. Interest emerged in investigating fuzzy soft operators, results and
Salim Dawood Mohsen
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On Properties of Class A(n) and n‐Paranormal Operators
Abstract and Applied Analysis, Volume 2014, Issue 1, 2014., 2014 Let n be a positive integer, and an operator T ∈ B(ℋ) is called a class A(n) operator if T1+n2/1+n≥|T|2 and n‐paranormal operator if T1+nx1/1+n≥||Tx|| for every unit vector x ∈ ℋ, which are common generalizations of class A and paranormal, respectively.
Xiaochun Li, Fugen Gao, Changsen Yang
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Some results on composition operators on ℓ2
International Journal of Mathematics and Mathematical Sciences, 1979 A necessary and sufficient condition for a bounded operator to be a composition operator is investigated in this paper. Normal, quasi-hyponormal, paranormal composition operators are characterised.
R. K. Singh, D. K. Gupta, B. S. Komal
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