Results 21 to 30 of about 486 (86)
Inequalities for certain powers of positive definite matrices
Mathematical Inequalities & Applications, 2019 Let A,B, and X be n× n matrices such that A,B are positive definite and X is Hermitian. If a and b are real numbers such that 0 < a sn (A) and 0 < b sn (B) , then it is shown, among other inequalities, that ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣AX +XBa ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣ (1 ...
Fadi Alrimawi, O. Hirzallah, F. Kittaneh
semanticscholar +1 more source
A note on norm inequalities for positive operators
Journal of Inequalities and Applications, 2014 In this short note, we present a generalization of a norm inequality due to Bhatia and Kittaneh (Lett. Math. Phys. 43:225-231, 1998), which is also a refinement and a generalization of a result obtained by Kittaneh (Commun. Math. Phys. 104:307-310, 1986).
Jiewu Huang, Yang Peng, L. Zou
semanticscholar +2 more sources
On the reverse Young and Heinz inequalities
, 2017 In this paper, we study further improvements of the reverse Young and Heinz inequalities for positive real numbers. We use these modified inequalities to obtain corresponding operator inequalities and matrix inequalities on the Hilbert–Schmidt norm ...
M. Ghaemi +2 more
semanticscholar +1 more source
Walks and the spectral radius of graphs [PDF]
, 2006 We give upper and lower bounds on the spectral radius of a graph in terms of the number of walks. We generalize a number of known results.Comment: Corrections were made in Theorems 5 and 11 (the new numbers are different), following a remark of ...
Nikiforov, Vladimir
core +2 more sources
An S-type upper bound for the largest singular value of nonnegative rectangular tensors
Open Mathematics, 2016 An S-type upper bound for the largest singular value of a nonnegative rectangular tensor is given by breaking N = {1, 2, … n} into disjoint subsets S and its complement. It is shown that the new upper bound is smaller than that provided by Yang and Yang (
Zhao Jianxing, Sang Caili
doaj +1 more source
New bounds for the minimum eigenvalue of 𝓜-tensors
Open 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
New bounds for the minimum eigenvalue of M-matrices
Open Mathematics, 2016 Some new bounds for the minimum eigenvalue of M-matrices are obtained. These inequalities improve existing results, and the estimating formulas are easier to calculate since they only depend on the entries of matrices.
Wang Feng, Sun Deshu
doaj +1 more source
THE HYPERBOLIC QUADRATIC EIGENVALUE PROBLEM
Forum 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
Matrix Young numerical radius inequalities
, 2013 In the present paper, we show that if A ∈Mn(C) is a non scalar strictly positive matrix such that 1 ∈ σ(A) , and p > q > 1 with p + q = 1, then there exists X ∈ Mn(C) such that ω(AXA) > ω( p A pX + q XA q) .
A. Salemi, A. Sheikhhosseini
semanticscholar +1 more source
Functional centrality in graphs [PDF]
, 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