Accelerating the Hybrid Monte Carlo algorithm

TL;DR

This paper introduces a modified Hybrid Monte Carlo algorithm that separates high- and low-frequency modes using a split pseudo-fermion action and different evolution time-scales, achieving over threefold speed-up in simulations.

Contribution

It proposes a novel approach to accelerate HMC by splitting the pseudo-fermion action and using distinct time-scales, improving efficiency in gauge theory simulations.

Findings

Over threefold speed-up in typical simulations

Effective separation of frequency modes in HMC

Validated with two-flavor Wilson fermions

Abstract

An algorithm for separating the high- and low-frequency molecular dynamics modes in Hybrid Monte Carlo simulations of gauge theories with dynamical fermions is presented. The separation is based on splitting the pseudo-fermion action into two parts, as was initially proposed by Hasenbusch. We propose to introduce different evolution time-scales for each part. We test our proposal in realistic simulations of two-flavor O(a) improved Wilson fermions. A speed-up of more than a factor of three compared to the standard HMC algorithm is observed in a typical run.