Wohlmuth, Barbara I.; Krause, Rolf H. A multigrid method based on the unconstrained product space for mortar finite element discretizations. (English) Zbl 0992.65142 SIAM J. Numer. Anal. 39, No. 1, 192-213 (2001). The authors introduce a new mortar setting which combines the idea of dual basis functions with standard multigrid techniques for symmetric positive definite systems. This new setting is the starting point for the introduction of a multigrid method. The performance of the method is supported by some numerical experiments in 2D and 3D domains, including discontinuous coefficients and some corner singularities. Reviewer: Calin Ioan Gheorghiu (Cluj-Napoca) Cited in 11 Documents MSC: 65N55 Multigrid methods; domain decomposition for boundary value problems involving PDEs 35J25 Boundary value problems for second-order elliptic equations 35R05 PDEs with low regular coefficients and/or low regular data 65N30 Finite element, Rayleigh-Ritz and Galerkin methods for boundary value problems involving PDEs 65N15 Error bounds for boundary value problems involving PDEs Keywords:mortar finite elements; Lagrange multiplier; dual spaces; nonmatching triangulations; multigrid methods; level dependent bilinear forms; numerical experiments; discontinuous coefficients; corner singularities Software:UG PDFBibTeX XMLCite \textit{B. I. Wohlmuth} and \textit{R. H. Krause}, SIAM J. Numer. Anal. 39, No. 1, 192--213 (2001; Zbl 0992.65142) Full Text: DOI