The Adaptive Aggregation-based Domain Decomposition Multigrid method (arXiv:1303.1377) is extended for two degenerate flavors of twisted mass fermions. By fine-tuning the parameters we achieve a speed-up of the order of hundred times compared to the conjugate gradient algorithm for the physical value of the pion mass. A thorough analysis of the aggregation parameters is presented, which provides a novel insight into multigrid methods for lattice QCD independently of the fermion discretization.
@article{arxiv.1610.02370,
title = {Adaptive Aggregation-based Domain Decomposition Multigrid for Twisted Mass Fermions},
author = {Constantia Alexandrou and Simone Bacchio and Jacob Finkenrath and Andreas Frommer and Karsten Kahl and Matthias Rottmann},
journal= {arXiv preprint arXiv:1610.02370},
year = {2016}
}