Journal or Book Title
Electronic Journal of Linear Algebra
In this paper it is shown that a partial sign symmetric P-matrix, whose digraph of specified entries is a symmetric n-cycle with n ≥ 6, can be completed to a sign symmetric P-matrix. The analogous completion property is also established for a partial weakly sign symmetric P-matrix and for a partial weakly sign symmetric P0-matrix. Patterns of entries for 4 × 4 matrices are classified as to whether or not a partial (weakly) sign symmetric P- or weakly sign symmetric P0-matrix specifying the pattern must have completion to the same type of matrix. The relationship between the weakly sign symmetric P- and sign symmetric P-matrix completion problems is also examined.
DeAlba, Luz Maria; Hardy, Timothy L.; Hogben, Leslie; and Wangsness, Amy, "The (weakly) sign symmetric P-matrix completion problems" (2003). Mathematics Publications. 255.