Results 51 to 60 of about 816 (94)
Positivity of Partitioned Hermitian Matrices with Unitarily Invariant Norms
, 2014 We give a short proof of a recent result of Drury on the positivity of a $3\times 3$ matrix of the form $(\|R_i^*R_j\|_{\rm tr})_{1 \le i, j \le 3}$ for any rectangular complex (or real) matrices $R_1, R_2, R_3$ so that the multiplication $R_i^*R_j$ is ...
Li, Chi-Kwong, Zhang, Fuzhen
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Operator inequalities of Jensen type
Topological Algebra and its Applications, 2013 We present some generalized Jensen type operator inequalities involving sequences of self-adjoint operators.
Moslehian M. S., Mićić J., Kian M.
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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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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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THE GROTHENDIECK CONSTANT IS STRICTLY SMALLER THAN KRIVINE’S BOUND
Forum of Mathematics, Pi, 2013 The (real) Grothendieck constant ${K}_{G} $ is the infimum over those $K\in (0, \infty )$ such that for every $m, n\in \mathbb{N} $ and every $m\times n$ real matrix $({a}_{ij} )$ we have $$\begin{eqnarray*}\displaystyle \max _{\{ x_{i}\} _{i= 1}^{m} , \{
MARK BRAVERMAN +3 more
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Further refinements of the Cauchy-Schwarz inequality for matrices [PDF]
, 2014 Let $A, B$ and $X$ be $n\times n$ matrices such that $A, B$ are positive semidefinite. We present some refinements of the matrix Cauchy-Schwarz inequality by using some integration techniques and various refinements of the Hermite--Hadamard inequality ...
Bakherad, Mojtaba
core
, 2008 Results on matrix canonical forms are used to give a complete description of the higher rank numerical range of matrices arising from the study of quantum error correction.
Li, Chi-Kwong, Sze, Nung-Sing
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Some inequalities for unitarily invariant norms of matrices
Journal of Inequalities and Applications, 2011 This article aims to discuss inequalities involving unitarily invariant norms. We obtain a refinement of the inequality shown by Zhan. Meanwhile, we give an improvement of the inequality presented by Bhatia and Kittaneh for the Hilbert-Schmidt norm ...
Wang Shaoheng, Zou Limin, Jiang Youyi
doaj
The perturbation of Drazin inverse and dual Drazin inverse
Special MatricesIn this study, we derive the Drazin inverse (A+εB)D{\left(A+\varepsilon B)}^{D} of the complex matrix A+εBA+\varepsilon B with Ind(A+εB)>1{\rm{Ind}}\left(A+\varepsilon B)\gt 1 and Ind(A)=k{\rm{Ind}}\left(A)=k and the group inverse (A+εB)#{\left(A ...
Wang Hongxing, Cui Chong, Wei Yimin
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Concrete minimal 3 × 3 Hermitian matrices and some general cases
Demonstratio Mathematica, 2017 Given a Hermitian matrix M ∈ M3(ℂ) we describe explicitly the real diagonal matrices DM such that ║M + DM║ ≤ ║M + D║ for all real diagonal matrices D ∈ M3(ℂ), where ║ · ║ denotes the operator norm.
Klobouk Abel H., Varela Alejandro
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