Speaker
Description
Motivated by recent studies of light QCD axions in dense nuclear matter, in this talk, we will discuss the effects of the light QCD axion on gravitational observables of neutron stars: mass, radius, and tidal deformability. It has been shown that at sufficiently high baryon densities, finite density corrections to the axion potential source an axion field. We provide a numerical study of the dynamics of the light QCD axion in neutron stars, including the frictional effects of the gravitational self-interactions of the axion field. This analysis shows that the mass-radius relationship of the star can be affected at the ~3% level while the tidal deformability-compactness relationship can be affected at the ~10% level. We comment on the potential for axion studies with future gravitational wave observations of neutron star physics, possible electromagnetic probes of the light QCD axion, and future examination of direct effects of the light QCD axion on the baryonic equation of state in a NS.
