21 Analysis of Two-Level Overlapping Additive Schwarz Preconditioners for a Discontinuous Galerkin Method

The Schwarz method refers to a general methodology, based on the idea of divide-and-conquer, for solving the systems of linear algebraic equations resulting from numerical dis-cretizations of partial differential equations. In the past fifteen years extensive research has been done on the method to solve different types of algebraic systems which arise from var