Results 11 to 20 of about 371 (52)

Inequalities related to Bourin and Heinz means with a complex parameter [PDF]

open access: yes, 2015
A conjecture posed by S. Hayajneh and F. Kittaneh claims that given A, B positive matrices, 0≤t≤1, and any unitarily invariant norm the following inequality holds{triple vertical-rule fence}AtB1-t+BtA1-t{triple vertical-rule fence}≤{triple vertical-rule ...
Bottazzi, Tamara Paula   +3 more
core   +3 more sources

Functional centrality in graphs [PDF]

open access: yes, 2006
In this paper we introduce the functional centrality as a generalization of the subgraph centrality. We propose a general method for characterizing nodes in the graph according to the number of closed walks starting and ending at the node.
A. Gutiérrez   +5 more
core   +2 more sources

New bounds for the minimum eigenvalue of 𝓜-tensors

open access: yesOpen Mathematics, 2017
A new lower bound and a new upper bound for the minimum eigenvalue of an 𝓜-tensor are obtained. It is proved that the new lower and upper bounds improve the corresponding bounds provided by He and Huang (J. Inequal.
Zhao Jianxing, Sang Caili
doaj   +1 more source

More eigenvalue problems of Nordhaus-Gaddum type [PDF]

open access: yes, 2014
Let $G$ be a graph of order $n$ and let $\mu_{1}\left(G\right) \geq \cdots\geq\mu_{n}\left(G\right) $ be the eigenvalues of its adjacency matrix. This note studies eigenvalue problems of Nordhaus-Gaddum type.
Nikiforov, Vladimir, Yuan, Xiying
core   +1 more source

A convergence analysis of SOR iterative methods for linear systems with weak H-matrices

open access: yesOpen Mathematics, 2016
It is well known that SOR iterative methods are convergent for linear systems, whose coefficient matrices are strictly or irreducibly diagonally dominant matrices and strong H-matrices (whose comparison matrices are nonsingular M-matrices).
Zhang Cheng-yi   +2 more
doaj   +1 more source

Two new eigenvalue localization sets for tensors and theirs applications

open access: yesOpen Mathematics, 2017
A new eigenvalue localization set for tensors is given and proved to be tighter than those presented by Qi (J. Symbolic Comput., 2005, 40, 1302-1324) and Li et al. (Numer. Linear Algebra Appl., 2014, 21, 39-50).
Zhao Jianxing, Sang Caili
doaj   +1 more source

Some new bounds of the minimum eigenvalue for the Hadamard product of an M-matrix and an inverse M-matrix

open access: yesOpen Mathematics, 2016
Some convergent sequences of the lower bounds of the minimum eigenvalue for the Hadamard product of a nonsingular M-matrix B and the inverse of a nonsingular M-matrix A are given by using Brauer’s theorem.
Zhao Jianxing, Sang Caili
doaj   +1 more source

THE HYPERBOLIC QUADRATIC EIGENVALUE PROBLEM

open access: yesForum of Mathematics, Sigma, 2015
The hyperbolic quadratic eigenvalue problem (HQEP) was shown to admit Courant–Fischer type min–max principles in 1955 by Duffin and Cauchy type interlacing inequalities in 2010 by Veselić.
XIN LIANG, REN-CANG LI
doaj   +1 more source

Linear combinations of graph eigenvalues

open access: yes, 2006
Let F(G) be a fixed linear combination of the k extremal eigenvalues of a graph G and of its complement. The problem of finding max{F(G):v(G)=n} generalizes a number of problems raised previously in the literature. We show that the limit max{F(G):v(G)=n}/
Nikiforov, Vladimir
core   +1 more source

Changes in signature induced by the Lyapunov mapping LA : X → AX + XAA±

open access: yes, 1989
International Journal of Mathematics and Mathematical Sciences, Volume 12, Issue 3, Page 503-506, 1989.
Tyler Haynes
wiley   +1 more source

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