Primordial black hole evolution in two-fluid cosmology

TL;DR

This paper explores how primordial black holes, modeled as a two-fluid system with radiation, influence early universe evolution, affecting scale factor and entropy depending on their initial mass distribution.

Contribution

It introduces a two-fluid cosmological model incorporating primordial black holes with various initial mass functions to study their impact on universe dynamics.

Findings

Certain black hole populations significantly alter the scale factor.

Primordial black holes can generate substantial entropy.

Initial mass functions determine the extent of cosmological effects.

Abstract

Several processes in the early universe might lead to the formation of primordial black holes with different masses. These black holes would interact with the cosmic plasma through accretion and emission processes. Such interactions might have affected the dynamics of the universe and generated a considerable amount of entropy. In this paper we investigate the effects of the presence of primordial black holes on the evolution of the early universe. We adopt a two-fluid cosmological model with radiation and a primordial black hole gas. The latter is modelled with different initial mass functions taking into account the available constraints over the initial primordial black hole abundances. We find that certain populations with narrow initial mass functions are capable to produce significant changes in the scale factor and the entropy.