Multi-level minimal residual smoothing: A family of general purpose multigrid acceleration techniques (Q1298668)

Multi-level minimal residual smoothing (MRS) is applied as a pre-optimization technique to accelerate standard multigrid convergence, that improves the current multigrid iterate by smoothing its corresponding residual before the latter is projected to the coarse grid. Different schemes are introduced for implementing the MRS technique on the finest grid and on the coarse grid, as well as several versions of the inexact MRS technique. Numerical examples illustrate the efficiency of the methods.