Fixed boundary conditions and phase transitions in pure gauge compact QED

TL;DR

This study uses lattice simulations with fixed boundary conditions to investigate phase transitions in pure gauge compact QED, suggesting a second order transition and implications for the theory's nature.

Contribution

It introduces fixed boundary conditions in lattice simulations of compact QED and analyzes their effects on phase transition behavior.

Findings

Identified a phase transition without discontinuity.

Evidence supports a second order phase transition.

Implications for the understanding of compact lattice QED.

Abstract

We have simulated the pure gauge compact QED with fixed boundary conditions, on lattices from $6^4$ to $16^4$. We argue that a lattice with this fixed boundary imposition corresponds actually to a lattice with spherical topology. We have found the presence of a phase transition without any trace of discontinuity. Moreover, the specific heat and the Binder cumulant are qualitatively consistent with a second order phase transition. The implications of this observation on the nature of the compact lattice QED are discussed.