A Nearly-Linear Time Algorithm for Approximately Solving Linear Systems in a Symmetric M-Matrix

We present an algorithm for solving a linear system in a symmetric M-matrix. In particular, for $n times n$ symmetric M-matrix $M$, we show how to find a diagonal matrix $D$ such that $DMD$ is diagonally-dominant. To compute $D$, the algorithm must solve $O{log n}$ linear systems in diagonally-dominant matrices. If we solve these diagonally-dominant systems approximately using the Spielman-Teng nearly-linear time solver, then we obtain an algorithm for approximately solving linear systems in symmetric M-matrices, for which the expected running time is also nearly-linear