# Primordial Black Holes from Cosmic Domain Walls

## TL;DR

This paper explores how primordial black holes formed from collapsing domain wall bubbles during inflation could account for dark matter and observed black hole mergers, offering a new formation mechanism with distinctive mass distributions.

## Contribution

It introduces a novel model where PBHs originate from quantum tunneling nucleated domain walls, resulting in a specific mass function and addressing uncertainties in PBH formation.

## Key findings

- PBHs from domain walls can constitute dark matter.
- Mass distribution of PBHs has a spike-like structure.
- PBHs can explain LIGO black hole merger events.

## Abstract

We investigate the formation of primordial black holes (PBHs) from the collapse of spherically symmetric domain wall bubbles, which spontaneously nucleate via quantum tunneling during inflation. Since the tension of domain walls changes with time and so domain walls nucleate in a short time interval, the mass function of PBHs in general has a spike-like structure. In contrast to models in which PBHs produced from overdense regions, our model avoids the uncertainties of PBHs production mechanism. PBHs from domain walls with mass around $10^{20}\mathrm{g}$ may constitute all dark matter, those with mass around $10^{34}\mathrm{g}$ can explain the merger events of binary black holes detected by LIGO.