Results 31 to 40 of about 2,183 (141)

Corrigendum to “Spectra universally realizable by doubly stochastic matrices”

open access: yesSpecial Matrices, 2023
We correct an error in the statement and the proof of Theorem 2.1 and Corollary 2.1 in our previous study [Spec. Matrices 6 (2018), 301–309], Section 2: On nonnegative matrices similar to positive matrices.
Collao Macarena   +2 more
doaj   +1 more source

Pseudoinverse formulation of Rayleigh‐Schrödinger perturbation theory for the symmetric matrix eigenvalue problem

open access: yesJournal of Applied Mathematics, Volume 2003, Issue 9, Page 459-485, 2003., 2003
A comprehensive treatment of Rayleigh‐Schrödinger perturbation theory for the symmetric matrix eigenvalue problem is furnished with emphasis on the degenerate problem. The treatment is simply based upon the Moore‐Penrose pseudoinverse thus distinguishing it from alternative approaches in the literature.
Brian J. McCartin
wiley   +1 more source

The expected adjacency and modularity matrices in the degree corrected stochastic block model

open access: yesSpecial Matrices, 2018
We provide explicit expressions for the eigenvalues and eigenvectors of matrices that can be written as the Hadamard product of a block partitioned matrix with constant blocks and a rank one matrix.
Fasino Dario, Tudisco Francesco
doaj   +1 more source

On the smallest singular value in the class of unit lower triangular matrices with entries in [−a, a]

open access: yesSpecial Matrices, 2021
Given a real number a ≥ 1, let Kn(a) be the set of all n × n unit lower triangular matrices with each element in the interval [−a, a]. Denoting by λn(·) the smallest eigenvalue of a given matrix, let cn(a) = min {λ n(YYT) : Y ∈ Kn(a)}.
Altınışık Ercan
doaj   +1 more source

Inequalities for M-tensors

open access: yes, 2014
In this paper, we establish some important properties of M-tensors. We derive upper and lower bounds for the minimum eigenvalue of M-tensors, bounds for eigenvalues of M-tensors except the minimum eigenvalue are also presented; finally, we give the Ky ...
Jun He, Tingzhu Huang
semanticscholar   +1 more source

The nonexistence of rank 4 IP tensors in signature (1, 3)

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 31, Issue 5, Page 259-269, 2002., 2002
Let V be a real vector space of dimension 4 with a nondegenerate symmetric bilinear form of signature (1, 3). We show that there exists no algebraic curvature tensor R on V so that its associated skew‐symmetric operator R(⋅) has rank 4 and constant eigenvalues on the Grassmannian of nondegenerate 2‐planes in V.
Kelly Jeanne Pearson, Tan Zhang
wiley   +1 more source

The Diagonalizable Nonnegative Inverse Eigenvalue Problem

open access: yesSpecial Matrices, 2018
In this articlewe provide some lists of real numberswhich can be realized as the spectra of nonnegative diagonalizable matrices but which are not the spectra of nonnegative symmetric matrices.
Cronin Anthony G, Laffey Thomas J.
doaj   +1 more source

Matrix splitting principles

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 28, Issue 5, Page 251-284, 2001., 2001
The systematic analysis of convergence conditions, used in comparison theorems proven for different matrix splittings, is presented. The central idea of this analysis is the scheme of condition implications derived from the properties of regular splittings of a monotone matrix A = M1 − N1 = M2 − N2.
Zbigniew I. Woźnicki
wiley   +1 more source

Updating a map of sufficient conditions for the real nonnegative inverse eigenvalue problem

open access: yesSpecial Matrices, 2019
The real nonnegative inverse eigenvalue problem (RNIEP) asks for necessary and sufficient conditions in order that a list of real numbers be the spectrum of a nonnegative real matrix.
Marijuán C.   +2 more
doaj   +1 more source

An Explicit Formula for the Matrix Logarithm

open access: yes, 2004
We present an explicit polynomial formula for evaluating the principal logarithm of all matrices lying on the line segment $\{I(1-t)+At:t\in [0,1]\}$ joining the identity matrix $I$ (at $t=0$) to any real matrix $A$ (at $t=1$) having no eigenvalues on ...
Cardoso, Joao R.
core   +2 more sources

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