Model-independent energy budget of cosmological first-order phase transitions

Understand

We study the energy budget of a first-order cosmological phase transition, which is an important factor in the prediction of the resulting gravitational wave spectrum.

• Formerly, this analysis was based mostly on simplified models as for example the bag equation of state.
• Here, we present a model-independent approach that is exact up to the temperature dependence of the speed of sound in the broken phase.
• We find that the only relevant quantities that enter in the hydrodynamic analysis are the speed of sound in the broken phase and a linear combination of the energy and pressure differences between the two phases which we call pseudotrace (normalized to the enthalpy in the broken phase).