Multigrid accelerated simulations for Twisted Mass fermions

Abstract

Simulations at physical quark masses are affected by the critical slowing down of the solvers. Multigrid preconditioning has proved to deal effectively with this problem. Multigrid accelerated simulations at the physical value of the pion mass are being performed to generate $N_f=2$ and $N_f=2+1+1$ gauge ensembles using twisted mass fermions. The adaptive aggregation-based domain decomposition multigrid solver, referred to as DD-$\alpha$AMG method, is employed for these simulations. Our simulation strategy consists of an hybrid approach of different solvers, involving the Conjugate Gradient (CG), multi-mass-shift CG and DD-$\alpha$AMG solvers. We present an analysis of the multigrid performance during the simulations discussing the stability of the method. This significant speeds up the Hybrid Monte Carlo simulation by more than a factor $4$ at physical pion mass compared to the usage of the CG solver.

8 pages, 5 figures, proceedings for LATTICE 2017

References in corpus (3)

• Accelerating Dynamical Fermion Computations using the Rational Hybrid Monte Carlo (RHMC) Algorithm with Multiple Pseudofermion Fields
• Adaptive multigrid algorithm for the lattice Wilson-Dirac operator
• Local coherence and deflation of the low quark modes in lattice QCD

Cited by in corpus (11)

• Complete flavor decomposition of the spin and momentum fraction of the proton using lattice QCD simulations at physical pion mass
• Proton and neutron electromagnetic form factors from lattice QCD
• Simulating twisted mass fermions at physical light, strange and charm quark masses
• Moments of nucleon generalized parton distributions from lattice QCD simulations at physical pion mass
• Nuclear matrix elements from lattice QCD for electroweak and beyond-Standard-Model processes
• Ratio of kaon and pion leptonic decay constants with $N_f=2+1+1$ Wilson-clover twisted-mass fermions
• Sparsening Algorithm for Multi-Hadron Lattice QCD Correlation Functions
• Multigrid approach in shifted linear systems for the non-degenerated twisted mass operator
• Model-independent determination of the nucleon charge radius from lattice QCD
• Kaon radiative leptonic decay rates from lattice QCD simulations at the physical point
• Topological observables and $\theta$ dependence in high temperature QCD from lattice simulations