Universal relations for binary neutron star mergers with long-lived remnants

Abstract

We present a novel universal relation for binary neutron star mergers with long-lived neutron star remnants: inspired by recent work based on numerical relativity simulations, we propose a novel approach using perturbative calculations that allow us to relate the premerger neutron star binary tidal deformability to the effective compactness of the postmerger remnant. Our results allow for the prediction of the stellar parameters of a long-lived remnant neutron star from the study of gravitational waves emitted during the premerger phase.