COMPUTATIONAL COMPLEXITY OF THE SCHWARZ ALTERNATING PROCEDURE
Abstract
This paper develops sharp convergence rate estimates of the Schwarz alternating procedure. We do this for a model Poisson problem in one and two dimensions with multiple subdomains We then use these estimates to assess the serial and parallel complexity of the optimal Schwarz algorithm. We finish with a comparison of this optimal algorithm, using multigrid as the subdomain solver, and multigrid by itself, without domain decomposition.