Neutron Star Equation of State Constrained by Gravitational Waves

A little over one year ago gravitational (GW170817) and electromagnetic waves emitted by a binary neutron star (BNS) merger were first observed. Analyses of these observations have led to new estimates of the maximum mass and canonical radius of neutron stars, placing strict constraints on the equation of state of dense matter. In this short talk we discuss the composition of neutron star matter in light of these new constraints, focusing on the possible presence of hyperons. We use an equation of state modeled using the relativistic mean-field approximation and parameterized for consistency with constraints from theoretical and experimental nuclear physics and neutron star observations. We find that hyperonic neutron star matter is not ruled out by analyses of the BNS merger, but that the presence and abundance of hyperons depend on the choice of the vector meson-hyperon coupling constants.