I'm searching for robust smoothers for geometric multigrids.
By robust I mean:
- Effective for high order approximations (say spectral element, spectral Discontinuous Galerkin),
- Parallel (suitable for co-processors),
- Effective for heterogeneity and anisotropy problems.
From what I can gather, Schwarz type smoothers may be promising (Fischer et al); and block/line/ plane, and ILU smoothers are also recommended (Trottenberg et al).
Are there any other state-of-the-art smoothers I should consider?