One-flavor algorithm for Wilson and domain-wall fermions

TL;DR

This paper develops positive-definite pseudofermion actions for single-flavor Wilson and domain-wall fermions, enabling efficient Hybrid Monte Carlo simulations and comparing their performance to multi-flavor setups.

Contribution

It introduces new pseudofermion actions for one-flavor fermions in lattice QCD, facilitating simulations with HMC and analyzing their efficiency.

Findings

Positive-definite actions for one-flavor fermions are constructed.

HMC simulation efficiency for optimal domain-wall quarks is compared.

Efficiency ratio between 2-flavor and (1+1)-flavor simulations is approximately 3:2.

Abstract

We construct positive-definite pseudofermion actions for one fermion flavor in lattice field theory, for Wilson and domain-wall fermions respectively. The positive definiteness of these actions ensures that they can be simulated with the Hybrid Monte Carlo (HMC) method. For lattice QCD with optimal domain-wall quarks, we compare the efficiency of HMC simulations of 2-flavor and (1+1)-flavor, and find that the efficiency ratio is about 3:2.