Abstract. The question of whether or not the product of two nonsingular n-by-nM-matrices has a nested sequence of positive principal minors (abbreviated to a nest) is considered. For n =2, 3, 4 such a product always has a nest, and this is conjectured for n = 5. For general n, examplesof products of two M-matrices with specified structure are identified as having a leading or trailing nest. For n = 4, it is shown that the cube of an M-matrix need not have a nest. Key words. M-matrix, Nested sequence of principal minors, P-matrix. AMS subject classifications. 15A15
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.