Ultralight Primordial Black Holes

TL;DR

This paper reviews the potential outcomes of ultralight primordial black holes, discussing whether they evaporate completely or leave stable relics, and explores the implications for detection and cosmology.

Contribution

It provides a comprehensive review of the theoretical scenarios for ultralight black hole evaporation and their observational consequences.

Findings

If evaporation stops, relics at the Planck scale may remain.

Complete evaporation could produce detectable high-energy signals.

Current status and future detection prospects are analyzed.

Abstract

The fate of ultralight black holes depends on whether or not evaporation stops at or around the Planck scale. If evaporation stops, the general expectation is that a population of Planck-scale will be left over, possibly including a significant fraction of electrically charged relics. If evaporation does not stop, a runaway "explosion" would occur, with significant and potentially detectable high-energy emission. Here, I review both possibilities, with an emphasis on current status and future detection prospects.