Results 21 to 30 of about 865 (99)
Operator inequalities via geometric convexity
Mathematical Inequalities & Applications, 2019 The main goal of this paper is to present new generalizations of some known inequalities for the numerical radius and unitarily invariant norms of Hilbert space operators.
M. Sababheh, H. Moradi, S. Furuichi
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Operators with minimal pseudospectra and connections to normality
, 2020 This paper mainly studies the class of bounded linear operators A with minimal pseudospectra σε (A) = σ(A)+Dε for some ε > 0 , where σ(A) denotes the spectrum of A , and Dε denotes the open disk of radius ε centered at the origin.
Samir Raouafi
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Berezin number inequalities for operators
Concrete Operators, 2019 The Berezin transform à of an operator A, acting on the reproducing kernel Hilbert space ℋ = ℋ (Ω) over some (non-empty) set Ω, is defined by Ã(λ) = 〉Aǩ λ, ǩ λ〈 (λ ∈ Ω), where k⌢λ=kλ‖kλ‖${\mathord{\buildrel{\lower3pt\hbox{$\scriptscriptstyle\frown ...
Bakherad Mojtaba, Garayev Mubariz T.
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Topological properties of the block numerical range of operator matrices
, 2020 We show that the block numerical range of an n×n -operator matrix A corresponding to an operator A on the Banach space X with respect to a decomposition X = ∏Xj has at most n connected components.
Agnes Radl, M. Wolff
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General numerical radius inequalities for matrices of operators
Open Mathematics, 2016 Let Ai ∈ B(H), (i = 1, 2, ..., n), and T=[0⋯0A1⋮⋰A200⋰⋰⋮An0⋯0] $ T = \left[ {\matrix{ 0 & \cdots & 0 & {A_1 } \cr \vdots & {\mathinner{\mkern2mu\raise1pt\hbox{.}\mkern2mu \raise4pt\hbox{.}\mkern2mu\raise7pt\hbox{.}\mkern1mu}} & {A_2 } & 0
Al-Dolat Mohammed +3 more
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Numerical Range on Weighted Hardy Spaces as Semi Inner Product Spaces
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2017 The semi-inner product, in the sense of Lumer, on weighted Hardy space which generate the norm is unique. Also we will discuss some properties of the numerical range of bounded linear operators on weighted Hardy spaces.
Heydari Mohammad Taghi
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Some Inequalities for Power Series of Selfadjoint Operators in Hilbert Spaces via Reverses of the Schwarz Inequality [PDF]
, 2009 In this paper we obtain some operator inequalities for functions defined by power series with real coefficients and, more specifically, with non- negative coefficients.
Dragomir, Sever S
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A class of tridiagonal operators associated to some subshifts
Open Mathematics, 2016 We consider a class of tridiagonal operators induced by not necessary pseudoergodic biinfinite sequences. Using only elementary techniques we prove that the numerical range of such operators is contained in the convex hull of the union of the numerical ...
Hernández-Becerra Christian +1 more
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Subdifferential of the joint numerical radius [PDF]
arXiv, 2022 An expression for the subdifferential of the joint numerical radius is obtained. Its applications to the best approximation problems in the joint numerical radius are discussed.
arxiv
Pre-images of Boundary Points of the Numerical Range
, 2014 This paper considers matrices A ∈ Mn(C) whose numerical range contains boundary points generated by multiple linearly independent vectors. Sharp bounds for the maximum number of such boundary points (excluding flat portions) are given for unitarily ...
Timothy Leake, Brian Lins, I. Spitkovsky
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