Dark matter effects on the properties of neutron stars: Compactness and tidal deformability

Abstract

We systematically study the observable properties of dark-matter admixed neutron stars with arbitrary dark-matter fraction, employing a realistic nuclear equation of state in combination with self-interacting fermionic dark matter respecting constraints on the self-interaction cross section. Deviations from universal relations valid for nucleonic neutron stars are analyzed over the whole parameter space of the model and unequivocal signals for the presence of dark matter in neutron stars are identified.