Fast Radio Bursts and Axion Miniclusters

Abstract

Non-linear effects in the evolution of the axion field in the early Universe may lead to the formation of gravitationally bound clumps of axions, known as "miniclusters". Minicluster masses should be in the range $M_{\rm mc}\sim10^{-12} M_\odot$, and in plausible early-Universe scenarios a significant fraction of the mass density of the Universe may be in the form of axion miniclusters. Here I argue that observed properties (total energy release, duration, high brightness temperature, event rate) of recently discovered Fast Radio Bursts can be matched in a model which assumes explosive decay of axion miniclusters.