# Primordial black holes from scalar field evolution in the early universe

## TL;DR

This paper explores how scalar field dynamics in the early universe, including condensate fragmentation and topological defects, can produce primordial black holes across a wide mass spectrum, potentially explaining LIGO observations.

## Contribution

It introduces a mechanism for primordial black hole formation from scalar field evolution, extending the mass range beyond previous limits, relevant for gravitational wave detections.

## Key findings

- Scalar condensates can fragment into Q-balls, leading to PBH formation.
- The mechanism can produce black holes from 1 to 100 solar masses.
- Topological defects can also generate PBHs through similar processes.

## Abstract

Scalar condensates with large expectation values can form in the early universe, for example, in theories with supersymmetry. The condensate can undergo fragmentation into Q-balls before decaying. If the Q-balls dominate the energy density for some period of time, statistical fluctuations in their number density can lead to formation of primordial black holes (PBH). In the case of supersymmetry the mass range is limited from above by $10^{23}$g. For a general charged scalar field, this robust mechanism can generate black holes over a much broader mass range, including the black holes with masses of 1-100 solar masses, which is relevant for LIGO observations of gravitational waves. Topological defects can lead to formation of PBH in a similar fashion.