Results 51 to 60 of about 486 (86)

On the boundary of weighted numerical ranges

, 2015
In this article, we are going to introduce the weighted numerical range which is a further generalization both the c-numerical range and the rank k numerical range.
Cheung, Wai-Shun
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Maxima Q-index of graphs with forbidden odd cycles [PDF]

, 2014
Let $q\left( G\right) $ be the $Q$-index (the largest eigenvalue of the signless Laplacian) of $G$. Let $S_{n,k}$ be the graph obtained by joining each vertex of a complete graph of order $k$ to each vertex of an independent set of order $n-k.$ The main ...
Yuan, Xiying
core  

Further refinements of the Cauchy-Schwarz inequality for matrices [PDF]

, 2014
Let $A, B$ and $X$ be $n\times n$ matrices such that $A, B$ are positive semidefinite. We present some refinements of the matrix Cauchy-Schwarz inequality by using some integration techniques and various refinements of the Hermite--Hadamard inequality ...
Bakherad, Mojtaba
core  

Extensions of inequalities involving Kantorovich constant

, 2011
In this paper, two methods of extending inequalities involving Kantorovich constant are presented. An inequality of Micic et al. [Linear Algebra Appl., 318 (2000), 87–107] on positive linear maps and geometric mean of positive definite matrices is ...
M. Niezgoda
semanticscholar   +1 more source

Maximum norms of graphs and matrices, and their complements

, 2013
In this paper, we mainly study the trace norm of the adjacency matrix of a graph, also known as the energy of graph. We give the maximum trace norms for the graph and its complement. In fact, the above problem is stated and solved in a more general setup
Nikiforov, Vladimir, Yuan, Xiying
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Estimating eigenvalues of matrices by induced norms

, 2011
A classical result of Konig in terms of matrices states that for 1 p 0 not depending on the matrix A , where ‖A‖q,p denotes the norm of A viewed as an operator from q into n p .
C. Michels
semanticscholar   +1 more source

Estimating matching distance between spectra

, 2009
We show that if a , b are elements of an unital Banach algebra such that almost all convex combinations of a and b have a finite spectrum of cardinality n , then the optimal matching distance between their spectra satisfies D(σ(a),σ(b)) cn (‖a‖+‖b‖)1−1/n
Abdelkrim Nokrane
semanticscholar   +1 more source

Matrix Hermite-Hadamard type inequalities [PDF]

, 2013
We present several matrix and operator inequalities of Hermite-Hadamard type. We first establish a majorization version for monotone convex functions on matrices. We then utilize the Mond-Pecaric method to get an operator version for convex functions. We
Moslehian, Mohammad Sal
core  

Error bound for a perturbed minimization problem related with the sum of smallest eigenvalues

, 2010
Let C be a n×n symmetric matrix. For each integer 1 < k < n we consider the minimization problem m(e): = minX{ Tr{CX} + eƒ(X)}. Here the variable X is an n×n symmetric matrix, whose eigenvalues satisfy the number e is a positive (perturbation) parameter ...
M. V. Travaglia
semanticscholar   +1 more source

Trace inequalities for multiple products of two matrices

, 2000
Trace inequalities for multiple products of powers of two matrices are discussed via the methodof logmajorization. For instance, the trace inequality |Tr(Ap1Bq1Ap2Bq2 · · ·ApK BqK )| Tr(AB) is obtained for positive semidefinite matrices A,B and pi, qi 0 ...
T. Andô, F. Hiai, K. Okubo
semanticscholar   +1 more source