Multigrid preconditioning in \(H(\text{div})\) on non-convex polygons
A multigrid preconditioner for the finite element discretization of the operator I-grad(div) is presented. The procedure is analyzed without the assumption that the domain is convex. It is shown that the preconditioner is spectrally equivalent to the inverse of the discrete operator.
scientific article; zbMATH DE number 1281838