BLASTs in Physical Review Letters

The article "Stimulated axion decay in superradiant  clouds around astrophysical black holes" (arXiv:1709.06581), co-authored by Gr@v member João Rosa and Tom Kephart (Vanderbilt University, USA), has been accepted for publication in Physical Review Letters and will be highlighted as one of the PRL Editors' Suggestions (a distinction attributed to about one in six Letters).

This article describes a new phenomenon, named BLASTs (Black hole Lasers powered by Axion SuperradianT instabilities), based on the stimulated decay of axions into photon pairs within the dense axion clouds formed around spinning primordial black holes due to the superradiant instability. For axions accounting for most of the dark matter in the Universe, and primordial black holes with around the Earth's mass, BLASTs correspond to extremely bright events in the GHz radio frequency range lasting for only a few milliseconds, potentially explaining the mysterious fast radio bursts that have been observed over the past decade.