Speaker
Description
We study the equation of state of neutron star matter using Bayesian inference based on multi-messenger observations, including pulsar mass measurements, NICER mass-radius constraints, and tidal deformability inferred from the gravitational-wave event GW170817. Hybrid equations of state are constructed by combining hadronic matter models with quark matter described by a nonlocal NJL model with color superconductivity.
The analysis shows that stable hybrid stars occur only in a limited region of parameter space. Using multi-messenger astronomy data, the Bayesian analysis allows us to constrain the Lagrangian parameters of quark matter. The results favor early deconfinement and indicate that up-to-date mass and radius measurements support the presence of large color-superconducting quark cores in neutron stars. Moreover, we find that hybrid equation of state are significantly more probable than purely hadronic one.