Results 81 to 90 of about 2,874 (210)

Sparsifying Sums of Positive Semidefinite Matrices

open access: yes
In this paper, we revisit spectral sparsification for sums of arbitrary positive semidefinite (PSD) matrices. Concretely, for any collection of PSD matrices $\mathcal{A} = \{A_1, A_2, \ldots, A_r\} \subset \mathbb{R}^{n \times n}$, given any subset $T \subseteq [r]$, our goal is to find sparse weights $μ\in \mathbb{R}_{\geq 0}^r$ such that $(1 - ε ...
Arpon Basu   +3 more
openaire   +2 more sources

Sparse Minimum Redundancy Maximum Relevance for Feature Selection

open access: yesScandinavian Journal of Statistics, EarlyView.
ABSTRACT We propose a feature screening method that integrates both feature–feature and feature–target relationships. Inactive features are identified via a penalized minimum Redundancy Maximum Relevance (mRMR) procedure, which is the continuous version of the classical mRMR penalized by a non‐convex regularizer, and where the parameters estimated as ...
Peter Naylor   +3 more
wiley   +1 more source

A permanent inequality for positive semidefinite matrices

open access: yesThe Electronic Journal of Linear Algebra, 2023
In this paper, we prove an inequality involving the permanent of a positive semidefinite matrix and its leading submatrices. We obtain a result in the similar spirit of Bapat-Sunder per-max conjecture.
openaire   +3 more sources

Inertia of partial transpose of positive semidefinite matrices [PDF]

open access: yes, 2023
We show that the partial transpose of $9\times 9$ positive semidefinite matrices do not have inertia (4,1,4) and (3,2,4). It solves an open problem in "LINEAR AND MULTILINEAR ALGEBRA, Changchun Feng et al, 2022".
Chen, Lin   +3 more
core   +1 more source

Frequency‐dependent contraction rates for the Bayesian method to the inverse source problem

open access: yesTransactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.
Abstract This paper addresses an inverse source problem for acoustic waves in a range of frequencies. Our study has two main goals. First, although the problem is severely ill‐posed with a logarithmic stability estimate, we demonstrate, through careful analysis of the forward map's singular values, that increasing the frequency range enhances stability,
Pu‐Zhao Kow, Jenn‐Nan Wang
wiley   +1 more source

Certain Positive Semidefinite Matrices of Special Functions [PDF]

open access: yes, 2018
Special functions are often defined as a Fourier or Laplace transform of a positive measure, and the positivity of the measure manifests as positive definiteness of certain matrices. The purpose of this expository note is to give a sample of such positive definite matrices to demonstrate this connection for some well-known special functions such as ...
openaire   +2 more sources

An Inequality for Positive Semidefinite Hermitian Matrices(1) [PDF]

open access: yes, 1974
Let A and B be positive semidefinite Hermitian n-square matrices. If A—B is positive semidefinite, write A≥B. Haynsworth [1] has proved that if A≥B then det(A+B)≥det A+n det B.Let G be a subgroup of the symmetric group, Sn, and let λ be a character on G.
Russell Merris
core   +1 more source

A Geometric Mean of Parameterized Arithmetic and Harmonic Means of Convex Functions

open access: yesAbstract and Applied Analysis, 2012
The notion of the geometric mean of two positive reals is extended by Ando (1978) to the case of positive semidefinite matrices A and B. Moreover, an interesting generalization of the geometric mean A # B of A and B to convex functions was introduced by ...
Sangho Kum, Yongdo Lim
doaj   +1 more source

Bayesian Implementation of the Factor‐Analytic Mixed Model and Application to Embeddings

open access: yesStat, Volume 15, Issue 3, September 2026.
ABSTRACT Mixed models and neural networks each offer complementary frameworks for prediction. Theoretically grounded in inference, mixed models can unveil latent variance structure notably with the factor‐analytic approach. In this article, we propose to bridge the gap between the two frameworks, leveraging embedding data from a neural network encoder ...
Alexandre Marchal   +3 more
wiley   +1 more source

Conjugate cone characterization of positive definite and semidefinite matrices [PDF]

open access: yes, 1984
Positive definite and semidefinite matrices are characterized in terms of positive definiteness and semidefiniteness on arbitrary closed convex cones in Rn.
Mangasarian, O.L., Han, S.-P.
core   +1 more source

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