Some Remarks on A Multigrid Preconditioner (Xu and Qin) ====================================================================== SIAM Journal on Scientific Computing Volume 15-1, January 1994, pp. 172-184 (C) 1994 by Society for Industrial and Applied Mathematics All rights reserved Title: Some Remarks on A Multigrid Preconditioner Author: Jinchao Xu and Jinshui Qin AMS Subject Classifications: 65F10, 65F35, 65M60, 65N30 Key words: finite element, hierarchical basis, multigrid, preconditioner ---- ABSTRACT This paper is devoted to a class of multilevel preconditioners developed in [{\it Math Comp}., 55 (1990), pp.\ 1--22] by Bramble, Pasciak, and Xu and in the Ph.D.\ thesis of Xu at Cornell University, Ithaca, NY, 1989. A simple proof is given for optimal estimation of the conditioning. A derivation of matrix representations and a description of efficient implementation techniques are also given. Some modified preconditioners are proposed combining the hierarchical basis method. Numerical examples are also given that compare various preconditioners discussed in this paper. ====================================================================== SIAM 3600 University City Science Center Philadelphia, PA 19104-2688, USA Phone: 215-382-9800, 800-447-7426 (USA only) Fax: 215-386-7999 E-mail: journals@siam.org