Bubble Growth as a Detonation

TL;DR

This paper demonstrates that the Chapman-Jouguet constraint does not restrict bubble growth in cosmological first-order phase transitions, allowing a broader class of detonation solutions, including weak detonations, beyond the Jouguet type known from chemical burning. By developing a relativistic hydrodynamic framework with Taub jump conditions and detonation/shock adiabats, it classifies possible growth modes and proves the impossibility of strong detonations and strong deflagrations, while showing weak detonations arise naturally under sufficient supercooling. Through 1+1 dimensional models and a dissipative surface parameter, it shows how deflagration-to-detonation transitions can occur and discusses potential cosmological consequences such as large-scale inhomogeneities behind detonations. The study emphasizes that front velocities are set by microscopic physics at the phase boundary rather than conservation laws alone, marking a key difference from chemical burning.

Abstract

Bubble growth as a detonation is studied in the context of cosmological phase transitions. It is proved that the so called Chapman-Jouguet hypothesis, which restricts the types of detonations that can occur in spherically symmetric chemical burning, does not hold in the case of phase transitions. Therefore a much larger class of detonation solutions exists in phase transitions than in chemical burning.