Terrestrial Signals from Axion Star Explosions (and other relativistic bursts)

by Dr Josh Eby (Kavli IPMU)

Thursday 24 Nov 2022, 16:00 → 17:30 Asia/Seoul

1423 in building 1 (KIAS)

Title: Terrestrial Signals from Axion Star Explosions (and other relativistic bursts)

Speaker: Josh Eby (Kavli IPMU)

Abstract: Axions form gravitationally-bound structures called axion stars, which are astrophysical objects with unique observational signatures. When an axion star grows enough in mass, it collapses gravitationally, and in its final moments it emits a large fraction of its energy in relativistic axions; we show that these axion bursts are detectable in proposed future axion dark matter experiments. Unlike the cold dark matter signal, the signal from axion star explosions is not suppressed by the axion decay constant ∝1/f, due to a cancellation with the energy emission ∝f, making this a promising avenue to discover axions with GUT-scale decay constants. Our calculation is easily extendable to other sources of relativistic bursts of axions, including superradiant cloud collapse or collision / merger processes, which we plan to investigate in the future.