Results 31 to 40 of about 71,800 (235)

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 these ...
Latif N, Pečarić J, Anwar M
doaj   +2 more sources

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

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 Sparse Decomposition of Low Rank Symmetric Positive Semidefinite Matrices [PDF]

open access: yesMultiscale Modeling & simulation, 2016
Suppose that $A \in \mathbb{R}^{N \times N}$ is symmetric positive semidefinite with rank $K \le N$. Our goal is to decompose $A$ into $K$ rank-one matrices $\sum_{k=1}^K g_k g_k^T$ where the modes $\{g_{k}\}_{k=1}^K$ are required to be as sparse as ...
T. Hou, Qin Li, Pengchuan Zhang
semanticscholar   +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

Generic Spectrahedral Shadows [PDF]

open access: yes, 2015
Spectrahedral shadows are projections of linear sections of the cone of positive semidefinite matrices. We characterize the polynomials that vanish on the boundaries of these convex sets when both the section and the projection are generic.Comment ...
Sinn, Rainer, Sturmfels, Bernd
core   +1 more source

Metric geometric means with arbitrary weights of positive definite matrices involving semi-tensor products

open access: yesAIMS Mathematics, 2023
We extend the notion of classical metric geometric mean (MGM) for positive definite matrices of the same dimension to those of arbitrary dimensions, so that usual matrix products are replaced by semi-tensor products.
Arnon Ploymukda, Pattrawut Chansangiam
doaj   +1 more source

Logarithmic barriers for sparse matrix cones

open access: yes, 2012
Algorithms are presented for evaluating gradients and Hessians of logarithmic barrier functions for two types of convex cones: the cone of positive semidefinite matrices with a given sparsity pattern, and its dual cone, the cone of sparse matrices with ...
Andersen, Martin S.   +2 more
core   +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

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

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