Black holes and gravitational waves from phase transitions in realistic models

TL;DR

This paper investigates how second-order corrections in bubble nucleation rates affect primordial black hole formation and gravitational wave predictions in realistic phase transition models, highlighting the importance of higher-order effects.

Contribution

It introduces the necessity of second-order corrections in bubble nucleation rate calculations for accurate PBH and GW predictions in phase transition models.

Findings

Second-order corrections significantly alter PBH abundance estimates.

Higher-order terms make fluctuation distributions more Gaussian.

Different GW spectra can result from models with identical PBH abundances.

Abstract

We study realistic models predicting primordial black hole (PBH) formation from density fluctuations generated in a first-order phase transition. We show that the second-order correction in the expansion of the bubble nucleation rate is necessary for accurate predictions and quantify its impact on the abundance of PBHs and gravitational waves (GWs). We find that the distribution of the fluctuations becomes more Gaussian as the second-order term increases. Consequently, models that predict the same PBH abundances can produce different GW spectra.