Phase transition of photons and gravitons in a Casimir box

TL;DR

This paper analytically investigates a first order phase transition for photons and gravitons in a Casimir box, highlighting symmetry breaking, Bose-Einstein condensation, and a quantum phase transition driven by optical helicity's chemical potential.

Contribution

It provides a detailed analytical study of phase transitions involving photons and gravitons in a Casimir setup, linking boundary conditions to symmetry breaking and quantum phase phenomena.

Findings

Identification of a first order phase transition in the system

Connection between boundary conditions and symmetry breaking

Quantum phase transition controlled by optical helicity's chemical potential

Abstract

A first order phase transition for photons and gravitons in a Casimir box is studied analytically from first principles with a detailed understanding of symmetry breaking due to the boundary conditions. It is closely related to Bose-Einstein condensation and accompanied by a quantum phase transition whose control parameter is the chemical potential for optical helicity.