Completions of partial P-matrices with acyclic or non-acyclic associated graph

AbstractIn this paper we analyze the positive (sign-symmetric) P-matrix completion problem when the pattern of the partial matrix is non-symmetric. We prove that every positive (sign-symmetric) partial P-matrix A has a positive (sign-symmetric) P-matrix completion when the associated graph of the specified entries of A, GA, is acyclic and we study special cases when GA is not acyclic