Signatures of primordial black hole dark matter

TL;DR

This paper explores primordial black holes as a candidate for dark matter, discussing their formation, observational constraints, and potential roles in cosmic reionization, galaxy formation, and gamma-ray sources, linking early Universe physics to observable phenomena.

Contribution

It proposes that primordial black holes formed during cosmological phase transitions could be the dominant dark matter component and serve as probes for high-energy physics in the early Universe.

Findings

PBHs can form in a narrow mass range around 10^{17}g.

PBHs could explain reionization at redshifts 5-10.

PBH clusters may seed galaxy formation and account for gamma-ray sources.

Abstract

The nonbaryonic dark matter of the Universe is assumed to consist of new stable forms of matter. Their stability reflects symmetry of micro world and mechanisms of its symmetry breaking. In the early Universe heavy metastable particles can dominate, leaving primordial black holes (PBHs) after their decay, as well as the structure of particle symmetry breaking gives rise to cosmological phase transitions, from which massive black holes and/or their clusters can originate. PBHs can be formed in such transitions within a narrow interval of masses about $10^{17}$g and, avoiding severe observational constraints on PBHs, can be a candidate for the dominant form of dark matter. PBHs in this range of mass can give solution of the problem of reionization in the Universe at the redshift $z\sim 5... 10$. Clusters of massive PBHs can serve as a nonlinear seeds for galaxy formation, while PBHs evaporating in such clusters can provide an interesting interpretation for the observations of point-like gamma-ray sources. Analysis of possible PBH signatures represents a universal probe for super-high energy physics in the early Universe in studies of indirect effects of the dark matter.