Adaptive Aggregation-based Domain Decomposition Multigrid for Twisted Mass Fermions

TL;DR

This paper extends an adaptive multigrid method for twisted mass fermions in lattice QCD, achieving significant speed-ups over traditional algorithms and providing new insights into multigrid parameter tuning.

Contribution

It introduces an extended adaptive aggregation-based multigrid method for twisted mass fermions and analyzes parameter effects, enhancing computational efficiency in lattice QCD.

Findings

Achieves up to 100x speed-up over conjugate gradient methods.

Provides a detailed analysis of aggregation parameters.

Offers new insights into multigrid methods independent of fermion discretization.

Abstract

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.