A multigrid algorithm for the mortar finite element method. (English) Zbl 0942.65139

The authors consider the mortar method as a special domain decomposition method in order to solve second order elliptic boundary value problems. They establish the inf-sup condition for the saddle point formulation and they are able to verify optimal multigrid efficiency. Some numerical experiments confirm the theoretical results and show the efficiency and robustness of the proposed algorithm even in situations not covered by the theory.


65N55 Multigrid methods; domain decomposition for boundary value problems involving PDEs
65F10 Iterative numerical methods for linear systems
65N30 Finite element, Rayleigh-Ritz and Galerkin methods for boundary value problems involving PDEs
35J25 Boundary value problems for second-order elliptic equations


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