THE M_0 – MATRIX COMPLETION PROBLEM FOR DIGRAPHS OF 5×5 MATRICES WITH LESS THAN FOUR DIRECTED LINES

Abstract

A real matrix is said to be – matrix if its principal minors are non - negative and all its non - diagonal entries are non - positive. In this project, we consider the – matrix completion problem. It is shown that any digraph with less than four directe d lines which is not a cycle has – completion. It is further shown that digraph of matrix with less than four directed lines which is a cycle does not have – completion.