Adaptive Algebraic Multigrid for Lattice QCD

Who: Andreas Frommer (University of Wuppertal)
When: Monday, March 27, 2017 at 14:15
Where: The CP³ meeting room

In this talk we will first present the general idea behind multigrid approaches as an efficient means for solving linear systems of equations arising from discretizations of partial differential equations In the Lattice QCD context, new developments are necessary in order to account for the additional difficulties that arise due to the fluctuating gauge fields. Recent breakthroughs were obtained by applying a self-adaptive, bootstrap principle exposing the small eigenmodes which are then used to determine appropriate coarse grid operators. This approach turns out to be efficient for the Wilson-Dirac operator as well as for the Twisted Mass operator, and it also provides a means for the preconditioning of the so-called overlap operator.