Gauge non-invariance as tests of emergent gauge symmetry

TL;DR

This paper explores how small violations of gauge symmetry can serve as tests for emergent gauge symmetry, especially in gravity, and discusses potential links to Lorentz invariance violations.

Contribution

It proposes a method to test for emergent gauge symmetry by detecting symmetry violations and discusses their possible connection to Lorentz invariance violations.

Findings

Violations of gauge symmetry can indicate emergent gauge phenomena.

Testing for small gauge violations can differentiate fundamental from emergent symmetries.

Potential link between gauge symmetry violations and Lorentz invariance violations.

Abstract

We motivate the concept of emergent gauge symmetry and discuss ways that this concept can be tested. The key idea is that if a symmetry is emergent, one should look for small violations of this symmetry because the underlying fundamental theory does not contain the symmetry. We describe our recent work implementing this idea in the gravity sector. We also describe the reasons why violations of gauge symmetry may well be linked to violations of Lorentz invariance.