Speaker
Description
Abstract
Axion stars, gravitationally bound states of low-energy axions, described by a field theory with potential energy $f^2 m^2(1-Cos (A/f))$ have
a maximum mass allowed by gravitational stability. Weakly bound states
obtaining this maximum mass have sufficiently large radii such that they are
dilute, and as a result, they are well described by a leading-order expansion
of the axion potential. Heavier states are susceptible to gravitational
collapse. Inclusion of higher-order interactions, present in the full
potential, can give qualitatively different results in the analysis of
collapsing heavy states, as compared to the leading-order expansion. In this
work, we find that collapsing axion stars are stabilized by repulsive
interactions present in the full potential, providing evidence that such
objects do not form black holes. These dense configurations, which are the
endpoints of collapse, have extremely high binding energy, and as a result,
quickly decay through number changing interactions.
