Results 11 to 20 of about 70,365 (263)
BOUNDED AND UNBOUNDED OPERATORS SIMILAR TO THEIR ADJOINTS
Bulletin of the Korean Mathematical Society, 2017 08 ...
Dehimi, Souheyb, Mortad, Mohammed Hichem
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Commutativity up to a factor for bounded and unbounded operators
Journal of Mathematical Analysis and Applications, 2014 In this paper, we further investigate the problem of commutativity up to a factor (or $ $-commutativity) in the setting of bounded and unbounded linear operators in a complex Hilbert space. The results are based on a new approach to the problem. We finish the paper by a conjecture on the commutativity of self-adjoint operators.
Chellali, Chérifa +1 more
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Right (Or Left) Invertibility of Bounded and Unbounded Operators and Applications to the Spectrum of Products [PDF]
Complex Analysis and Operator Theory, 2017 This paper is mainly concerned with proving $ (AB)= (BA)$ for two linear and non necessarily bounded operators $A$ and $B$. The main tool is left and right invertibility of bounded and unbounded operators.
Dehimi, Souheyb, Mortad, Mohammed Hichem
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Journal of Functional Analysis, 1993 A linear unbounded operator \(B\) on a Banach space \(X\) whose spectrum is contained in an open set \(V\) is said to be of \(\alpha\)-type \(V\) if \((w- B)^{-1}\) exists for \(w\not\in V\) and is \(O((1+ | w|)^ \alpha)\) for some \(\alpha\geq -1\). For such operators the author defines a functional calculus \(f\mapsto f(B)\) defined for holomorphic ...
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Invertibility and Fredholm Property of Fock Toeplitz Operators
Mathematics, 2023 We characterize some necessary and sufficient conditions of invertible Toeplitz operators acting on the Fock space. In particular, we study the Fredholm properties of Toeplitz operators with BMO1 symbols, where their Berezin transforms are bounded ...
Chunxu Xu, Tao Yu
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The Perturbations of Weyl’s Theorems for Unbounded Class-A Operators
Journal of Kufa for Mathematics and Computer, 2023 The significance of Weyl's spectrum is regional to the perturbation theory but recently it is related to operator theory in some theorems. The study of Weyl’s theorem has so far limited to the class of bounded operators, however, lately this study has ...
Dalia Sami Ali, Buthainah A. Ahmed
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Theory of B(X)-Module: Algebraic Module Structure of Generally Unbounded Infinitesimal Generators
Advances in Mathematical Physics, 2020 The concept of logarithmic representation of infinitesimal generators is introduced, and it is applied to clarify the algebraic structure of bounded and unbounded infinitesimal generators.
Yoritaka Iwata
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Rate of Convergence for a New Family of Summation-Integral Beta Operators [PDF]
المجلة العراقية للعلوم الاحصائية, 2011 In the present paper, we define a new family of summation-integral Beta operators to approximate a class of unbounded continuous functions of polynomial growth , for some and then we estimate the rate of convergence for this family for functions have ...
Ali J. Mohammad and Ansam A. Abdul-Rahman
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Approximation of functions with linear positive operators which fix {1, φ} and {1, φ2}
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2020 In this manuscript, linear and positive operators described on bounded and unbounded intervals that fix the function sets {1, φ} and {1, φ2} such that φ ∈ C[0, 1] are presented. Then we present different types of operators by choosing different functions
Usta Fuat
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Kolmogorov type inequalities for the Marchaud fractional derivatives on the real line and the half-line [PDF]
, 2014 In this paper we establish some new Kolmogorov type inequalities for the Marchaud and Hadamard fractional derivatives of functions defined on a real axis or semi-axis.
Babenko, V. F. +3 more
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