Theory HEP Seminar

A Hot Metallic Hydrogen Cloud Around QCD Axion Stars

Joshua Berger

University of Wisconsin-Madison

Axion stars are compact, dense clumps of axions that can form during the cosmological evolution of the universe. Given their small size, their effects on cosmological observables are negligible. We demonstrate that primordial axion stars can accumulate a cloud of baryons. Furthermore, this cloud of baryons could reach a sufficiently dense state that it can burn axions and become hot. This leads to potential point source observables with a blackbody spectrum peaked over a range of frequencies depending on the axion star properties.