Results 41 to 50 of about 448 (54)

Support-based lower bounds for the positive semidefinite rank of a nonnegative matrix [PDF]

open access: yes, 2013
The positive semidefinite rank of a nonnegative $(m\times n)$-matrix~$S$ is the minimum number~$q$ such that there exist positive semidefinite $(q\times q)$-matrices $A_1,\dots,A_m$, $B_1,\dots,B_n$ such that $S(k,\ell) = \mbox{tr}(A_k^* B_\ell)$.
Dirk, Oliver Theis, Troy Lee
core  

Perron Spectratopes and the Real Nonnegative Inverse Eigenvalue Problem

open access: yes, 2015
Call an $n$-by-$n$ invertible matrix $S$ a \emph{Perron similarity} if there is a real non-scalar diagonal matrix $D$ such that $S D S^{-1}$ is entrywise nonnegative.
Johnson, Charles R., Paparella, Pietro
core   +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  

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

The totally nonnegative part of G/P is a ball

open access: yes, 2019
We show that the totally nonnegative part of a partial flag variety (in the sense of Lusztig) is homeomorphic to a closed ball.Comment: 6 pages. v2: Proof of Lemma 1 moved to arXiv:1707.02010.
Galashin, Pavel   +2 more
core  

Infinitely divisible nonnegative matrices, $M$-matrices, and the embedding problem for finite state stationary Markov Chains

open access: yes, 2017
This paper explicitly details the relation between $M$-matrices, nonnegative roots of nonnegative matrices, and the embedding problem for finite-state stationary Markov chains.
Van-Brunt, Alexander
core  

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