[dune-pdelab] Implementing OVLP_AMG_4_DG solver

[Lukas Riedel]

Dear all,

I’m trying to ‘go parallel’ with our instationary DG solver by implementing the OVLP_AMG_4_DG linear solver. I use UG and YaspGrid as grid backends. Apparently, UG does not support Overlap, but only Ghosts. Can I still use this linear solver in both cases or do I need different solver implementations for the two grids?

I use PkLocalFiniteElementMap (UG grid only) or QkDGLocalFiniteElementMap (UG & Yasp) for my solution (DG) GFS. For the solver to work, I understand that I have to assemble another (CG) GFS with the same FEMs, but with polynomial order 0. Which EntitySet and which Constraints should I use for the two GridFunctionSpaces? Does this choice depend on the type of Grid used?

Thank you in advance!
Cheers,
Lukas