On the detectability of primordial black holes in the Galaxy

TL;DR

This paper explores the potential electromagnetic signals from primordial black holes in the Galaxy, concluding that low-mass PBHs are undetectable through passages, but high-mass PBHs could be captured and produce observable effects.

Contribution

It provides a novel analysis of PBH interactions with astrophysical objects, highlighting the detectability prospects for high-mass PBHs as dark matter candidates.

Findings

Passage signals from PBHs are undetectable due to low interaction probability or energy loss.

High-mass PBHs (>1e26 g) can be captured within the Hubble time, potentially leading to observable effects.

PBHs could contribute up to ~10% to dark matter density at high masses.

Abstract

In the mass range of 1e15 g up to 1e26 g, primordial black holes (PBHs) as a possible contribution to the dark matter are still unexplored. In this contribution, we investigate the possibility of an electromagnetic signal from PBH interactions with astrophysical objects in the Galaxy. We find that a signal from passages cannot be observed, since, depending on the mass, either the interaction probability or the energy loss is too small. Further, we discuss possible effects from high-mass PBHs at masses >1e26 g, where PBHs can still contribute to the dark matter at the order of ~10%. Here, we find that a significant fraction of PBHs can be captured in the Hubble time. These captures could therefore lead to detectable effects.