Block alternating group explicit preconditioning (blage) for a class of fourth order difference schemes

Abstract

We consider the block alternating group explicit method (BLAGE) as a preconditioner for a class of unsymmetric linear systems arising from fourth order finite difference schemes. An advantage of the preconditioner proposed is that the preconditioning operations can be divided into several subproblems which can then be run in parallel. The BLAGE preconditioner is shown to be extremely effective in achieving optimal convergence rates for the class of unsymmetric fourth order difference schemes considered in this paper

Keywords:

• block alternating group explicit method
• Krylov subspace methods
• preconditioning
• fourth order discretisations

C.R.Categories:

• G 1.3
• G 1.7