Dark matter dilution scenarios in the early universe

TL;DR

This paper investigates how entropy production during the electroweak phase transition and primordial black hole evaporation can dilute dark matter density in the early universe, affecting dark matter abundance predictions.

Contribution

It provides calculations of the dilution factor for dark matter due to entropy influx from phase transitions and black hole evaporation, exploring their impact on cosmological models.

Findings

Dilution factors can significantly reduce dark matter density predictions.

Entropy injection from phase transitions and black hole evaporation affects dark matter relic abundance.

The results help refine constraints on dark matter models in early universe scenarios.

Abstract

When the vacuum like energy of the Higgs potential within the standard model undergoes electroweak phase transition, an influx of entropy into the primordial plasma can lead to a significant dilution of frozen out dark matter density that was already present before the onset of the phase transition. The same effect can take place, if the early Universe was dominated by primordial black holes of small mass, evaporating before the period of Big Bang Nucleosynthesis. In this paper we calculate the dilution factor for the above mentioned scenarios.