Fast and accurate multigrid solution of Poissons equation using diagonally oriented grids

We solve Poissons equation using new multigrid algorithms that converge rapidly. The novel feature of the 2D and 3D algorithms are the use of extra diagonal grids in the multigrid hierarchy for a much richer and effective communication between the levels of the multigrid. Numerical experiments solving Poissons equation in the unit square and unit cube show simpl