Finite temperature phase transition in the 4d compact U(1) lattice gauge theory

TL;DR

This paper investigates the phase diagram of 4d compact U(1) lattice gauge theory, focusing on the nature of phase transitions and the potential for a continuum limit, with evidence indicating a first-order bulk transition at zero temperature.

Contribution

It provides new evidence that the T=0 bulk phase transition in 4d compact U(1) gauge theory is first-order, enhancing understanding of its phase structure and continuum limit prospects.

Findings

The T=0 bulk phase transition is strongly indicated to be first-order.

The phase diagram depends on the number of Euclidean time slices.

The helicity modulus effectively probes phase transitions.

Abstract

We study the phase diagram of the 4d compact U(1) gauge theory as a function of the number of Euclidean time slices. We use the helicity modulus as order parameter to probe the phase transitions. The order of the transition along the phase boundaries is studied and the possibility of a continuum limit is discussed. We present new, strong evidence that the T=0 bulk phase transition is first-order.