An exact Polynomial Hybrid Monte Carlo algorithm for dynamical Kogut-Susskind fermions

TL;DR

This paper introduces an exact polynomial Hybrid Monte Carlo algorithm for simulating dynamical Kogut-Susskind fermions, effectively removing systematic errors via polynomial approximation and noisy Metropolis testing, and demonstrating its efficiency on moderate lattice sizes.

Contribution

The paper develops a new exact PHMC algorithm for Kogut-Susskind fermions using polynomial approximation and noisy Metropolis test, improving simulation accuracy.

Findings

Works on a 16^4 lattice at β=5.7, m=0.02

Removes systematic errors with Kennedy-Kuti test

Achieves reasonable computational time for moderate lattices

Abstract

We present a polynomial Hybrid Monte Carlo (PHMC) algorithm as an exact simulation algorithm with dynamical Kogut-Susskind fermions. The algorithm uses a Hermitian polynomial approximation for the fractional power of the KS fermion matrix. The systematic error from the polynomial approximation is removed by the Kennedy-Kuti noisy Metropolis test so that the algorithm becomes exact at a finite molecular dynamics step size. We performed numerical tests with $N_f$$=$2 case on several lattice sizes. We found that the PHMC algorithm works on a moderately large lattice of $16^4$ at $\beta$$=$5.7, $m$$=$0.02 ($m_{\mathrm{PS}}/m_{\mathrm{V}}$$\sim$0.69) with a reasonable computational time.