Observations of compact stars and fermion-boson stars with a quartic self-interaction

Abstract

We investigated the possibility that neutron stars could be described by a fermion-boson star with a quartic self-interaction in the boson sector. Specifically, by varying the polytropic constant K and adiabatic index Γ in the polytropic equation of state, the boson mass µ, and the self-interaction parameter Λ, we construct equilibrium configurations of these mixed-stars with total mass compatible with the mass constraints obtained from observational data of NICER, NICER/XMN-Newton, and LIGO-VIRGO collaborations. Our work confirms that the addition of a boson sector eases the comparison of neutron star models with gravitational events related to compact objects and that in such a case observations may have preference for a positive self-interaction in the boson sector.