Results 31 to 40 of about 99 (60)
Numerical radius inequalities associated with the Cartesian decomposition
, 2015 We give several sharp numerical radius inequalities associated with the Cartesian decomposition of a Hilbert space operator A = B + iC . Among other inequalities, it is shown that 1 2 ‖ |B| + |C|‖ wr(A) ‖ |B| + |C|‖ for 0 < r 2 , where w(·) and ...
F. Kıttaneh
semanticscholar +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
Operator radii and unitary operators
, 2010 Let ρ 1 and wρ(A) be the operator radius of a linear operator A . Suppose m is a positive integer. It is shown that for a given invertible linear operator A acting on a Hilbert space, one has wρ (A−m) wρ (A)−m .
T. Andô, Chi-Kwong Li
semanticscholar +1 more source
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
Generalized finite operators and orthogonality
SUT Journal of Mathematics, 2011 In this paper we prove that a spectraloid operator is finite, we present some generalized finite operators and we give a new class of finite op- erators. Also, the orthogonality of some operators is studied.
S. Bouzenada
semanticscholar +1 more source
Algebraic properties of the set of operators with 0 in the closure of the numerical range
, 2013 Sets of operators which have zero in the closure of the numerical range are studied. For some particular sets T ⊆B(H ) , we characterize the set of all operators A ∈B(H ) such that 0 ∈W(TA) for every T ∈ T .
C. Diogo
semanticscholar +1 more source
Matrices with defect index one
, 2013 In this paper, we give some characterizations of matrices which have defect index one. Recall that an n -by-n matrix A is said to be of class Sn (resp., S −1 n ) if its eigenvalues are all in the open unit disc (resp., in the complement of closed unit ...
Cheng Chang +4 more
semanticscholar +1 more source
Normalized numerical ranges of some operators
, 2009 We describe the normalized numerical ranges of certain operators. First, the case of a normal operator, acting in a two dimensional space is considered in detail, leading to the general Kantorovich inequality.
L. Gevorgyan
semanticscholar +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
Genetic aberrations in glioblastoma multiforme: translocation of chromosome 10 in an O-2A-like cell line. [PDF]
Br J Cancer, 1999 Mao X +9 more
europepmc +1 more source