Non-Singularity Conditions for Two Z-Matrix Types

• 作者: Shinji Miura
• 来源期刊: 线性代数与矩阵理论研究进展(英文)
• 学科: 数学
• 关键词: Z-MATRIX M-MATRIX Non-Negative Matrix DIAGONAL DOMINANCE
• 年，卷（期）: xxdsyjzllyjjzyw,（2）
• 页码范围: 109-119
• 页数: 11页
• 分类号: O1

摘要

A real square matrix whose non-diagonal elements are non-positive is called a Z-matrix. This paper shows a necessary and sufficient condition for non-singularity of two types of Z-matrices. The first is for the Z-matrix whose row sums are all non-negative. The non-singularity condition for this matrix is that at least one positive row sum exists in any principal submatrix of the matrix. The second is for the Z-matrix which satisfies where . Let be the ith row and the jth column element of , and be the jth element of . Let be a subset of which is not empty, and be the complement of if is a proper subset. The non-singularity condition for this matrix is such that or such that for? . Robert Beauwens and Michael Neumann previously presented conditions similar to these conditions. In this paper, we present a different proof and show that these conditions can be also derived from theirs.