Beyond Standard Model equation of state and primordial black holes

TL;DR

This paper explores how modifications to the early universe's equation of state, due to beyond Standard Model particles, can significantly increase primordial black hole formation rates, with potential enhancements up to 20 orders of magnitude.

Contribution

It calculates the equations of state for various beyond Standard Model theories and assesses their impact on primordial black hole production.

Findings

Primordial black hole formation can be exponentially enhanced by changes in the equation of state.

Supersymmetric and composite Higgs models predict large degrees of freedom affecting black hole abundance.

Enhancements in black hole formation rates can reach up to 20 orders of magnitude.

Abstract

The Standard Model of particle physics successfully describes all known fundamental particles and their interactions; however, it leaves several unanswered questions. Theories beyond the Standard Model typically introduce new particles and symmetries to address these issues. In the early universe, when such particles become non-relativistic, or the symmetries are broken, there are associated reductions in the equation of state of the primordial plasma. These reductions lead to an exponential enhancement in the formation rate of primordial black holes. In this paper, we calculate the equation of state for several supersymmetric and composite Higgs models, which naturally predict a large number of additional degrees of freedom. Using these equations of state, we compute some example primordial black hole abundances, which we find can be enhanced by up to 20 orders of magnitude.