Recent rapid progress in neutron-star (NS) observations offers great potential to constrain the properties of strongly interacting matter under the most extreme conditions. In order to fully exploit the current observational inputs and to study the impact of future observations of NS masses, radii, and tidal deformabilities, we analyze a large ensemble of randomly generated viable NS-matter equations of state (EOSs) and the corresponding rotating stellar structures. We discuss the compatibility and impact of various hypotheses and measurements on the EOS, including those involving the merger product of the gravitational-wave (GW) event GW170817 and radius measurements of the pulsar PSR J0740 + 6620. We find that the conservative hypothesis that the remnant in GW170817 ultimately collapsed to a black hole strongly constrains the EOS and the maximal mass of NSs, implying M_TOV < 2.53M_⊙ (or M_TOV < 2.19M_⊙ if we assume that a hypermassive NS was created). Finally, we find that the recent NICER results for the radius of the massive NS PSR J0740 + 6620 place strong constraints for the behavior of the EOS.
Organized by: Edoardo Giangrandi