Results 21 to 30 of about 450 (52)
Domaine Numérique du produit AB avec A normal [PDF]
, 2006 2000 Mathematics Subject Classification: 18B30, 47A12.Let A, B be two linear operators on a complex Hilbert space H. We extend a Bouldin's result (1969) conserning W(AB) - the numerical range of the product AB. We show, when AB = BA and A is normal, than
Kaadoud, Mohamed Chraïbi
core
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.
core +1 more source
On Berezin norm and Berezin number inequalities for sum of operators
Demonstratio MathematicaThe aim of this study is to obtain several inequalities involving the Berezin number and the Berezin norm for various combinations of operators acting on a reproducing kernel Hilbert space.
Altwaijry Najla +2 more
doaj +1 more source
Inequalities for the Norm and Numerical Radius of Composite Operators in Hilbert Spaces [PDF]
, 2005 Some new inequalities for the norm and the numerical radius of composite operators generated by a pair of operators are given.Comment: 12 ...
Dragomir, Sever Silvestru
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Pinchings and Positive linear maps
, 2015 We employ the pinching theorem, ensuring that some operators A admit any sequence of contractions as an operator diagonal of A, to deduce/improve two recent theorems of Kennedy-Skoufranis and Loreaux-Weiss for conditional expectations onto a masa in the ...
Bourin, Jean-Christophe, Lee, Eun-Young
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Bounds of numerical radius of bounded linear operator using $t$-Aluthge transform
, 2020 We develop a number of inequalities to obtain bounds for the numerical radius of a bounded linear operator defined on a complex Hilbert space using the properties of $t$-Aluthge transform.
bag, Santanu +2 more
core
Crouzeix's conjecture, compressions of shifts, and classes of nilpotent matrices
Concrete OperatorsThis article studies the level set Crouzeix (LSC) conjecture, which is a weak version of Crouzeix’s conjecture that applies to finite compressions of the shift.
Bickel Kelly +4 more
doaj +1 more source
On the numerical radius of the truncated adjoint Shift [PDF]
, 2012 A celebrated thorem of Fejer (1915) asserts that for a given positive trigonometric polynomial $\sum_{j=-n+1}^{n-1}c_{j}e^{ijt}$, we have $\lvert c_{1}\lvert\leqslant c_{0}\cos\frac{\pi}{n+1}$. A more recent inequality due to U. Haagerup and P.
Gaaya, Haykel
core
, 2002 There exist operators $A$ such that : for any sequence of contractions $\{A_n\}$, there is a total sequence of mutually orthogonal projections $\{E_n\}$ such that $\Sigma E_nAE_n=\bigoplus A_n$.Comment: 11 ...
Bourin, Jean-Christophe
core +1 more source
A three monoclonal antibody combination potently neutralizes multiple botulinum neurotoxin serotype F subtypes. [PDF]
PLoS One, 2017 Fan Y +8 more
europepmc +1 more source