Results 11 to 20 of about 1,468 (179)

An elementary proof of Chollet’s permanent conjecture for 4 × 4 real matrices

open access: yesSpecial Matrices, 2021
A proof of the statement per(A ∘ B) ≤ per(A)per(B) is given for 4 × 4 positive semidefinite real matrices. The proof uses only elementary linear algebra and a rather lengthy series of simple inequalities.
Hutchinson George
doaj   +1 more source

Analysis of Fixing Nodes Used in Generalized Inverse Computation

open access: yesAdvances in Electrical and Electronic Engineering, 2014
In various fields of numerical mathematics, there arises the need to compute a generalized inverse of a symmetric positive semidefinite matrix, for example in the solution of contact problems.
Pavla Hruskova
doaj   +1 more source

Positive Semidefinite Matrices, Exponential Convexity for Majorization, and Related Cauchy Means

open access: yesJournal of Inequalities and Applications, 2010
We prove positive semidefiniteness of matrices generated by differences deduced from majorization-type results which implies exponential convexity and log-convexity of these differences and also obtain Lyapunov's and Dresher's inequalities for ...
N. Latif   +2 more
doaj   +2 more sources

Poisson Quantum Information [PDF]

open access: yesQuantum, 2021
By taking a Poisson limit for a sequence of rare quantum objects, I derive simple formulas for the Uhlmann fidelity, the quantum Chernoff quantity, the relative entropy, and the Helstrom information.
Mankei Tsang
doaj   +1 more source

A New Algorithm for Positive Semidefinite Matrix Completion

open access: yesJournal of Applied Mathematics, 2016
Positive semidefinite matrix completion (PSDMC) aims to recover positive semidefinite and low-rank matrices from a subset of entries of a matrix. It is widely applicable in many fields, such as statistic analysis and system control.
Fangfang Xu, Peng Pan
doaj   +1 more source

A counterexample to the Drury permanent conjecture

open access: yesSpecial Matrices, 2017
We offer a counterexample to a conjecture concerning the permanent of positive semidefinite matrices. The counterexample is a 4 × 4 complex correlation matrix.
Hutchinson George
doaj   +1 more source

Hilbert’s 17th problem in free skew fields

open access: yesForum of Mathematics, Sigma, 2020
This paper solves the rational noncommutative analogue of Hilbert’s 17th problem: if a noncommutative rational function is positive semidefinite on all tuples of Hermitian matrices in its domain, then it is a sum of Hermitian squares of noncommutative ...
Jurij Volčič
doaj   +1 more source

A Characterization on Singular Value Inequalities of Matrices

open access: yesJournal of Function Spaces, 2020
We obtain a characterization of pair matrices A and B of order n such that sjA≤sjB, j=1, …, n, where sjX denotes the j-th largest singular values of X. It can imply not only some well-known singular value inequalities for sums and direct sums of matrices
Wei Dai, Yongsheng Ye
doaj   +1 more source

有关矩阵广义逆的惯性指数及其应用(Inertia formulae related to the generalized inverse with applications)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2019
In this paper, firstly, we establish the inertia formulae for some matrix expressions related to the generalized inverse . Then, as applications, based on the derived inertia formulae, we study the definiteness of some matrices.
WUZhongcheng(吴中成)   +1 more
doaj   +1 more source

The resolvent average for positive semidefinite matrices

open access: yesLinear Algebra and its Applications, 2010
We define a new average - termed the resolvent average - for positive semidefinite matrices. For positive definite matrices, the resolvent average enjoys self-duality and it interpolates between the harmonic and the arithmetic averages, which it approaches when taking appropriate limits. We compare the resolvent average to the geometric mean.
Bauschke, Heinz H.   +2 more
openaire   +3 more sources

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