Section: New Results

A robust coarse space for Optimized Schwarz methods SORAS-GenEO-2

Optimized Schwarz methods (OSM) are very popular methods which were introduced by P.L. Lions for elliptic problems and Després for propagative wave phenomena. In [18] , we have built a coarse space for which the convergence rate of the two-level method is guaranteed regardless of the regularity of the coefficients. We do this by introducing a symmetrized variant of the ORAS (Optimized Restricted Additive Schwarz) algorithm and by identifying the problematic modes using two different generalized eigenvalue problems instead of only one as for the ASM (Additive Schwarz method), BDD (balancing domain decomposition) or FETI (finite element tearing and interconnection) methods.