Program package for multicanonical simulations of U(1) lattice gauge theory

TL;DR

This paper presents a Fortran 77 software package for multicanonical simulations of 4D U(1) lattice gauge theory, including tools for canonical and multicanonical sampling, with applications to phase transition studies.

Contribution

The paper introduces a versatile Fortran code for multicanonical simulations of lattice gauge theories, incorporating advanced algorithms like Wang-Landau recursion and overrelaxation.

Findings

Effective measurement of action and Polyakov loops.

Code features applicable to various lattice models.

Facilitates studies of phase transitions in gauge theories.

Abstract

We document our Fortran 77 code for multicanonical simulations of 4D U(1) lattice gauge theory in the neighborhood of its phase transition. This includes programs and routines for canonical simulations using biased Metropolis heatbath updating and overrelaxation, determination of multicanonical weights via a Wang-Landau recursion, and multicanonical simulations with fixed weights supplemented by overrelaxation sweeps. Measurements are performed for the action, Polyakov loops and some of their structure factors. Many features of the code transcend the particular application and are expected to be useful for other lattice gauge theory models as well as for systems in statistical physics.