Totally nonpositive completions on partial matrices

• Author(s): Araújo, C. Mendes ; Torregrosa, Juan R. ; Urbano, Ana M.
• Date: 2006
• Persistent ID: http://hdl.handle.net/1822/5741
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Partial matrix; Totally nonpositive matrix; Graph; Completion problems
• Document Type: Article
• Language: English

Description

An n £ n real matrix is said to be totally no positive if every minor is no positive. In this paper, we are interested in totally no positive completion problems, that is, does A partial totally no positive matrix have a totally no positive matrix completion? This Problem has, in general, a negative answer. Therefore, we analyze the question: for which Labelled graphs G does every partial totally no positive matrix, whose associated graph is G, have a totally no positive completion? Here we study the mentioned problem when G Is a choral graph or an undirected cycle.