Comparison of topology changing update algorithms

TL;DR

This paper compares alternative algorithms like metadynamics, instanton updates, and multiscale thermalization for sampling topological sectors in lattice simulations, highlighting their potential advantages over traditional methods.

Contribution

It evaluates the effectiveness of less common algorithms in sampling topological sectors, providing insights for their application in lattice gauge theories.

Findings

Metadynamics improves tunneling between topological sectors.

Instanton updates offer efficient sector sampling.

Multiscale thermalization enhances sampling at fine lattice spacings.

Abstract

In modern lattice simulations, conventional update algorithms do not allow for tunneling between topological sectors at fine lattice spacings. We compare the viability of multiple less commonly used algorithms (metadynamics, instanton updates, and multiscale thermalization) with respect to proper sampling of all topological sectors in the Schwinger model. We briefly comment on the prospects of applying these methods to 4-dimensional SU(3) simulations.