Haloes, other dark matter candidates and astrophysical implications

TL;DR

This paper discusses the possibility of multi-component dark matter models involving primordial black holes and other candidates, highlighting their unique astrophysical signatures and implications for detection and constraints.

Contribution

It explores the astrophysical implications of mixed dark matter models with primordial black holes and other candidates, emphasizing their potential observable signatures.

Findings

Primordial black holes may only constitute a fraction of dark matter.

Mixed models can produce distinctive astrophysical signals.

Current constraints leave open parameter space for other dark matter candidates.

Abstract

It is possible that a multi-component dark matter model is required if primordial black holes only contribute to a fraction of the energy density in dark matter. This is increasingly more likely with respect to the case of $f_{\rm PBH} = 1$, since there is only one remaining window, on asteroid-mass scales, where primordial black holes can make up all of the dark matter. A mixed dark matter model can lead to interesting observables that come about due to the interactions between primordial black holes and the second dark matter component. This can provide unique signatures of the presence of primordial black holes and increase the prospects of detection or improvement of constraints in the mass ranges where $f_{\rm PBH} < 1$, whilst simultaneously exploring the remaining open parameter space for other dark matter candidates.