Exponential reduction of finite volume effects with twisted boundary conditions

TL;DR

This paper demonstrates that flavor-twisted boundary conditions in lattice QCD can exponentially reduce finite volume artifacts for flavor-averaged observables, effectively mimicking larger volume effects.

Contribution

It introduces a specific flavor-twisted boundary condition scheme that significantly diminishes finite volume artifacts in lattice QCD calculations.

Findings

Finite volume artifacts are reduced to those of a four times larger periodic volume.

Destructive interference effects lead to exponential suppression of artifacts.

The method leverages phase averaging related to large N_c volume independence.

Abstract

Flavor-twisted boundary conditions can be used for exponential reduction of finite volume artifacts in flavor-averaged observables in lattice QCD calculations with $SU(N_f)$ light quark flavor symmetry. Finite volume artifact reduction arises from destructive interference effects in a manner closely related to the phase averaging which leads to large $N_c$ volume independence. With a particular choice of flavor-twisted boundary conditions, finite volume artifacts for flavor-singlet observables in a hypercubic spacetime volume are reduced to the size of finite volume artifacts in a spacetime volume with periodic boundary conditions that is four times larger.