Lions, P. L. On the Schwarz alternating method. I. (English) Zbl 0658.65090 Domain decomposition methods for partial differential equations, 1st Int. Symp., Paris/France 1987, 1-42 (1988). [For the entire collection see Zbl 0649.00019.] The paper is the first part of a series of three articles of the author on the Schwarz alternating method for solving partial differential equations. In the present first part, the author gives a variational interpretation of this method. The further two parts will be concerned with the maximum principle as a basic tool for the convergence analysis and with various variants of the method. In the present paper, the author starts from an interpretation of the Schwarz method as an iterated projection on closed subspaces connected with the domain decomposition method. This representation of the iterates immediately yields convergence and even convergence rate estimates. Then some quite interesting ideas for the parallelization of the Schwarz method are discussed. Finally, extensions of the method to nonlinear monotone problems, variational inequalities and evolution equations (parabolic and hyperbolic initial boundary value problems) are made. Reviewer: U.Langer Cited in 5 ReviewsCited in 127 Documents MSC: 65N22 Numerical solution of discretized equations for boundary value problems involving PDEs 65K10 Numerical optimization and variational techniques 65F10 Iterative numerical methods for linear systems 65N12 Stability and convergence of numerical methods for boundary value problems involving PDEs 35J65 Nonlinear boundary value problems for linear elliptic equations 49J40 Variational inequalities 35G10 Initial value problems for linear higher-order PDEs 35K25 Higher-order parabolic equations 35L20 Initial-boundary value problems for second-order hyperbolic equations 35J25 Boundary value problems for second-order elliptic equations 65Y05 Parallel numerical computation 65M99 Numerical methods for partial differential equations, initial value and time-dependent initial-boundary value problems 65N99 Numerical methods for partial differential equations, boundary value problems Keywords:Schwarz alternating method; iterated projection on closed subspaces; domain decomposition method; convergence rate estimates; parallelization; nonlinear monotone problems; variational inequalities; evolution equations Citations:Zbl 0649.00019 PDF BibTeX XML OpenURL