Reducing Residual-Mass Effects for Domain-Wall Fermions

TL;DR

This paper investigates a projection method to reduce residual chiral symmetry-breaking effects in domain-wall fermion simulations, demonstrating significant improvements in residual mass and fluctuation reduction across different gauge actions.

Contribution

The study provides evidence that projecting out low-lying eigenvalues effectively diminishes residual mass and fluctuations in domain-wall fermion simulations, enhancing their accuracy.

Findings

Significantly reduced residual mass with projection method

Disappearance of large fluctuations in residual mass

Effective across different gauge actions

Abstract

It has been suggested to project out a number of low-lying eigenvalues of the four-dimensional Wilson--Dirac operator that generates the transfer matrix of domain-wall fermions in order to improve simulations with domain-wall fermions. We investigate how this projection method reduces the residual chiral symmetry-breaking effects for a finite extent of the extra dimension. We use the standard Wilson as well as the renormalization--group--improved gauge action. In both cases we find a substantially reduced residual mass when the projection method is employed. In addition, the large fluctuations in this quantity disappear.