Domain Decomposition with Subdomain CCG for Material
                            Jump Elliptic Problems

                           Konstantin Lipnikov     

                      Institute of Numerical Mathematics
                         Russian Academy of Sciences
                                Gubkina st, 8
                                Moscow 117333
                                    Russia

                               Peter Deuflhard

           Konrad-Zuse-Zentrum für Imformationstechnic Berlin
                                 Takstrasse 7
                            D-14195 Berlin-Dahlem
                                   Germany

                                   Abstract

A combination of the cascadic conjugate gradient (CCG) method for homogeneous
problems wih non-overlapping domain decomposition (DD) method is studied.
Mortar finite elementson interfaces are applied to permit non-matching grids
in neighboring subdomains.  For material jump problems, the method is designed
as an alternative to the cascadic methods.