Results 11 to 20 of about 429 (36)
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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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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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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Lipschitz slices and the Daugavet equation for Lipschitz operators [PDF]
, 2014 We introduce a substitute for the concept of slice for the case of non-linear Lipschitz functionals and transfer to the non-linear case some results about the Daugavet and the alternative Daugavet equations previously known only for linear ...
Kadets, Vladimir +3 more
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The extremal algebra on two hermitians with square 1 [PDF]
, 2002 Let Ea(u,v) be the extremal algebra determined by two hermitians u and v with u2 = v2 = 1. We show that: Ea(u,v) = {f=gu:f,g ε C(T)}, where T is the unit circle; Ea(u,v) is C*-equivelant to C*(G), where G is the infinite dihedral group; most of the
Crabb, M.J., Duncan, J., McGregor, C.M.
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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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Decomposing numerical ranges along with spectral sets
, 2009 This note is to indicate the new sphere of applicability of the method developed by Mlak as well as by the author.
Szafraniec, F. H.
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Generalized Derivations and Norm Equality in Normed Ideals [PDF]
, 2011 2000 Mathematics Subject Classification: 47A10, 47A12, 47A30, 47B10, 47B20, 47B37, 47B47, 47D50.We compare the norm of a generalized derivation on a Hilbert space with the norm of its restrictions to Schatten norm ...
Barraa, Mohamed
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Numerical radius inequalities and its applications in estimation of zeros of polynomials
, 2019 We present some upper and lower bounds for the numerical radius of a bounded linear operator defined on complex Hilbert space, which improves on the existing upper and lower bounds. We also present an upper bound for the spectral radius of sum of product
Abu-Omar +19 more
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