Primordial Black Holes: Do They Exist and Are They Useful?

TL;DR

This paper reviews the current understanding of primordial black holes, exploring their potential formation, evaporation, and implications for early universe physics, quantum gravity, and high-energy phenomena, highlighting their significance as cosmic probes.

Contribution

It synthesizes recent developments on PBHs, emphasizing their role in constraining early universe conditions and fundamental physics, regardless of their actual existence.

Findings

PBHs could serve as probes of the early Universe

Constraints on high-energy physics from PBH studies

Implications for quantum gravity and gravitational collapse

Abstract

Recent developments in the study of primordial black holes (PBHs) are reviewed, with particular emphasis on their formation and evaporation. It is still not clear whether PBHs formed but, if they did, they could provide a unique probe of the early Universe, gravitational collapse, high energy physics and quantum gravity. Indeed their study may place interesting constraints on the physics relevant to these areas even if they never existed.