Results 21 to 30 of about 513 (80)
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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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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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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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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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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Constant norms and numerical radii of matrix powers
Operators and Matrices, 2019 For an n -by-n complex matrix A , we consider conditions on A for which the operator norms ‖Ak‖ (resp., numerical radii w(Ak) ), k 1 , of powers of A are constant.
Hwa-Long Gau, Kuo-Zhong Wang, P. Wu
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Sesquilinear version of numerical range and numerical radius
Acta Universitatis Sapientiae: Mathematica, 2017 In this paper by using the notion of sesquilinear form we introduce a new class of numerical range and numerical radius in normed space 𝒱, also its various characterizations are given. We apply our results to get some inequalities.
Moradi Hamid Reza +3 more
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An observation about normaloid operators
, 2017 Let H be a complex Hilbert space and B(H) the Banach space of all bounded linear operators on H . For any A ∈ B(H) , let w(A) denote the numerical radius of A . Then A is normaloid if w(A) = ‖A‖ .
J. Chan, K. Chan
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Sequences of bounds for the spectral radius of a positive operator
, 2019 In 1992, Szyld provided a sequence of lower bounds for the spectral radius of a nonnegative matrix $A$, based on the geometric symmetrization of powers of $A$.
Drnovšek, Roman
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