Renormalization group and triviality in noncompact lattice QED with light fermions

TL;DR

This paper investigates the triviality and renormalization group behavior of noncompact lattice QED with light fermions, revealing evidence for triviality in the weak coupling phase and non-triviality in the strong coupling phase.

Contribution

It derives the functional dependence of the average energy per plaquette on bare parameters using RG arguments and provides numerical evidence for triviality and non-triviality phases.

Findings

Evidence for triviality in the weak coupling phase.

Indication of a non-zero renormalized coupling in the strong coupling phase.

Numerical results on $8^4$ and $10^4$ lattices.

Abstract

In the framework of noncompact lattice QED with light fermions, we derive the functional dependence of the average energy per plaquette on the bare parameters using block-spin Renormalization Group arguments and assuming that the renormalized coupling vanishes. Our numerical results for this quantity in $8^4$ and $10^4$ lattices show evidence for triviality in the weak coupling phase and point to a non vanishing value for the renormalized coupling constant in the strong coupling phase.