Results 41 to 50 of about 541 (69)

Positivity of Partitioned Hermitian Matrices with Unitarily Invariant Norms

open access: yes, 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
core   +1 more source

Some inequalities for unitarily invariant norms of matrices

open access: yesJournal 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  

On Quasi-Normality of Two-Sided Multiplication [PDF]

open access: yes, 2009
2000 Mathematics Subject Classification: 47B47, 47B10, 47A30.In this note, we characterize quasi-normality of two-sided multiplication, restricted to a norm ideal and we extend this result, to an important class which contains all quasi-normal operators.
Amouch, M.
core  

A posteriori analysis of the spectral element discretization of heat equation

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2014
In this paper, we present a posteriori analysis of the discretization of the heat equation by spectral element method. We apply Euler’s implicit scheme in time and spectral method in space.
Chorfi Nejmeddine   +2 more
doaj   +1 more source

A simulation algorithm for a single server retrial queuing system with batch arrivals

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2015
Many systems of real word are modeled by retrial queuing system with batch arrivals. Analytical formulas for this class of systems are complicated and address only particular cases.
Florea Ion, Nǎnǎu Corina-Ştefania
doaj   +1 more source

On Berezin norm and Berezin number inequalities for sum of operators

open access: yesDemonstratio Mathematica
The 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

Further refinements of the Cauchy-Schwarz inequality for matrices [PDF]

open access: yes, 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  

Ideal norms and trigonometric orthonormal systems

open access: yes, 1994
In this article, we characterize the $UMD$--property of a Banach space $X$ by ideal norms associated with trigonometric orthonormal systems. The asymptotic behavior of that numerical parameters can be used to decide whether or not $X$ is a $UMD$--space.
Wenzel, Joerg
core   +2 more sources

About instability in an elastic Cosserat body with pores

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica
This article is centered on the study of the isotropic, porous Cosserat elastic media, realized by means of a parallel with the media of the same type, but anisotropic, by following the rewriting in a new form of the equations that govern this theory ...
Codarcea-Munteanu L.   +2 more
doaj   +1 more source

Operator inequalities related to weak 2-positivity [PDF]

open access: yes, 2012
In this paper we introduce the notion of weak 2-positivity and present some examples. We establish some operator Cauchy--Schwarz inequalities involving the geometric mean and give some applications. In particular, we present some operator versions of Hua'
Jun Ichi Fujii, Mohammad Sal, Moslehian
core  

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