Emergent gauge symmetries -- making symmetry as well as breaking it

TL;DR

This paper explores the concept of gauge symmetries as emergent phenomena in quantum many-body systems and discusses their potential implications for particle physics, including unification, Higgs phenomena, and cosmological constant issues.

Contribution

It reviews recent ideas on how gauge symmetries might emerge in particle physics from quantum many-body systems and their relevance to fundamental questions.

Findings

Emergent gauge symmetries appear in quantum phases with long-range entanglement.

Connections between emergent gauge phenomena and high-temperature superconductors, string-net condensation, and superfluid He-3.

Implications for unification, Higgs phenomena, and the cosmological constant puzzle.

Abstract

Gauge symmetries play an essential role in determining the interactions of particle physics. Where do they come from? Might the gauge symmetries of the Standard Model unify in the ultraviolet or might they be emergent in the infrared, below some large scale close to the Planck scale? Emergent gauge symmetries are important in quantum many-body systems in quantum phases associated with long range entanglement and topological order, e.g., they arise in high temperature superconductors, with string-net condensation and in the A-phase of superfluid He-3. String-nets and superfluid He-3 exhibit emergent properties similar to the building blocks of particle physics. Emergent gauge symmetries also play an important role in simulations of quantum field theories. This article discusses recent thinking on possible emergent gauge symmetries in particle physics, commenting also on Higgs phenomena and the vacuum energy or cosmological constant puzzle in emergent gauge systems.