Breakdown of hawking evaporation opens new mass window for primordial black holes as dark matter candidate

Abstract

ABSTRACT The energy injection through Hawking evaporation has been used to put strong constraints on primordial black holes as a dark matter candidate at masses below 1017 g. However, Hawking’s semiclassical approximation breaks down at latest after half-decay. Beyond this point, the evaporation could be significantly suppressed, as was shown in recent work. In this study we review existing cosmological and astrophysical bounds on primordial black holes, taking this effect into account. We show that the constraints disappear completely for a reasonable range of parameters, which opens a new window below 1010 g for light primordial black holes as a dark matter candidate.