Results 21 to 30 of about 51 (37)

The 123 theorem of Probability Theory and Copositive Matrices

open access: yesSpecial Matrices, 2014
Alon and Yuster give for independent identically distributed real or vector valued random variablesX, Y combinatorially proved estimates of the form Prob(∥X − Y∥ ≤ b) ≤ c Prob(∥X − Y∥ ≤ a). We derivethese using copositive matrices instead.
Kovačec Alexander   +2 more
doaj   +1 more source

Polynomials with a sharp Cauchy bound and their zeros of maximal modulus

open access: yes, 2015
The moduli of zeros of a complex polynomial are bounded by the positive zero of an associated auxiliary polynomial. The bound is due to Cauchy. This note describes polynomials with a sharp Cauchy bound and the location of peripheral zeros.
H. K. Wimmer
semanticscholar   +1 more source

Sufficient conditions for complete positivity

open access: yes, 2011
Marcus and Minc gave sufficient conditions on the diagonal entries of a doubly nonnegative doubly stochastic n×n matrix A , that there is a doubly nonnegative doubly stochastic matrix C with A = C2 . In this event, A is completely positive.
Robert Reams
semanticscholar   +1 more source

The integer cp-rank of 2 × 2 matrices

open access: yesSpecial Matrices, 2019
We show the cp-rank of an integer doubly nonnegative 2 × 2 matrix does not exceed 11.
Laffey Thomas, Šmigoc Helena
doaj   +1 more source

Notes and counterexamples on positive (semi) definite properties of some matrix products

open access: yesAin Shams Engineering Journal, 2018
In the present paper, we give some notes and counterexamples to show that the positive (semi) definite property of the Khatri-Rao and Tracy-Singh products of partitioned matrices are in general incorrect and show also that the matrix triangle inequality ...
Zeyad Al-Zhour
doaj   +1 more source

Singular M-matrices which may not have a nonnegative generalized inverse

open access: yesSpecial Matrices, 2014
A matrix A ∈ ℝn×n is a GM-matrix if A = sI − B, where 0 < ρ(B) ≤ s and B ∈WPFn i.e., both B and Bthave ρ(B) as their eigenvalues and their corresponding eigenvector is entry wise nonnegative.
Sushama Agrawal N.   +2 more
doaj   +1 more source

Completely positive matrices over Boolean algebras and their CP-rank

open access: yesSpecial Matrices, 2015
Drew, Johnson and Loewy conjectured that for n ≥ 4, the CP-rank of every n × n completely positive real matrix is at most [n2/4]. In this paper, we prove this conjecture for n × n completely positive matrices over Boolean algebras (finite or infinite ...
Mohindru Preeti
doaj   +1 more source

Hyponormality on a weighted Bergman space of an annulus with a general harmonic symbol

open access: yesOpen Mathematics
In this work we consider the hyponormality of Toeplitz operators on the Bergman space of the annulus with a logarithmic weight. We give necessary conditions when the symbol is of the form φ+ψ̄ $\varphi +\bar{\psi }$ where both φ and ψ are analytic on ...
Sadraoui Houcine, Halouani Borhen
doaj   +1 more source

Refined inertias of positive and hollow positive patterns

open access: yesSpecial Matrices
We investigate refined inertias of positive patterns and patterns that have each off-diagonal entry positive and each diagonal entry zero, i.e., hollow positive patterns. For positive patterns, we prove that every refined inertia (n+,n−,nz,2np)\left({n}_{
Berliner Adam H.   +3 more
doaj   +1 more source

Matrices having a positive determinant and all other minors nonpositive

open access: yesSpecial Matrices
The class of square matrices of order nn having a positive determinant and all their minors up to order n−1n-1 nonpositive is considered. A characterization of these matrices based on the Cauchon algorithm is presented, which provides an easy test for ...
Hassuneh Imad   +2 more
doaj   +1 more source

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