Shortly after the Big Bang, primordial black holes might have formed, which later collapsed into black holes and might explain the observation of supermassive and intermediate-mass black holes. After the first discovery of gravitational waves, interest in primordial black holes was rekindled, not only to account for the intermediate masses inferred for the black holes involved in the merger but also as potential dark matter candidates.
Florian Kühnel and Katherine Freese studied the impact of quantum fluctuations of the scalar field driving inflation on primordial black hole formation. They calculated the power and mass spectra for a field with inflection points, and found that primordial black hole formation is significantly enhanced. Hence, the effects of quantum fluctuations need to be taken into account when studying the formation of primordial black holes and their suitability as dark matter candidates.