# Sign-central matrices

- Authors
- Journal
- Linear Algebra and its Applications 0024-3795
- Publisher
- Elsevier
- Publication Date
- Identifiers
- DOI: 10.1016/0024-3795(94)90444-8
- Disciplines

## Abstract

Abstract We investigate real matrices A such that each matrix with the same sign pattern as A has a nonzero, nonnegative vector in its nullspace. For geometric reasons we call these matrices sign-central. These matrices were introduced and given a combinatorial characterization by Davydov and Davydova. We give an alternative proof of their characterization. We show that under a minimality assumption a sign-central matrix with m nonzero rows has at least m + 1 columns, and that equality holds if and only if the matrix is an S-matrix (as defined in the theory of sign-solvability).

## There are no comments yet on this publication. Be the first to share your thoughts.