Nonsymmetric Algebraic Riccati Equations and Wiener-Hopf Factorization for M-Matrices

We consider the nonsymmetric algebraic Riccati equation for which the four coefficient matrices form an M -matrix. Nonsymmetric algebraic Riccati equations of this type appear in applied probability and transport theory. The minimal nonnegative solution of these equations can be found by Newton’s method and basic fixed-point iterations. The study of these equations is also closely related to the so-called Wiener-Hopf factorization for M -matrices. We explain how the minimal nonnegative solution can be found by the Schur method and compare the Schur method with Newton’s method and some basic fixed-point iterations. The development in this paper parallels that for symmetric algebraic Riccati equations arising in linear quadratic control.