Adaptive Aggregation Based Domain Decomposition Multigrid for the Lattice Wilson Dirac Operator

Understand

In lattice QCD computations a substantial amount of work is spent in solving discretized versions of the Dirac equation.

• Conventional Krylov solvers show critical slowing down for large system sizes and physically interesting parameter regions.
• We present a domain decomposition adaptive algebraic multigrid method used as a precondtioner to solve the "clover improved" Wilson discretization of the Dirac equation.
• This approach combines and improves two approaches, namely domain decomposition and adaptive algebraic multigrid, that have been used seperately in lattice QCD before.