The equation of state for dense nucleonic matter from a meta-modeling (II): predictions for neutron stars properties

Employing a recently proposed meta-modeling for the equation of state for nucleonic matter we analyse neutron star global properties such as masses, radii, momentum of inertia, and others. The impact of the uncertainty on empirical parameters on these global properties is analysed in a Bayesian statistical approach. Physical constraints, such as causality and stability, are imposed on the equation of state and different hypotheses for the direct Urca (dUrca) process are investigated. Our main results are the following: the equation of state can be slightly softer if the dUrca is forbidden up to $2M_\odot$ {compared to cases where dUrca is allowed below $2M_\odot$}; neutron stars, if composed exclusively of nucleons and leptons, have a radius of 12.5$\pm$0.4~km (resp. 12.2$\pm$0.8~km) for masses ranging from 1 up to 1.6$M_\odot$ (resp. 1.6-2$M_\odot$) ; a small radius such as 11~km is still marginally compatible with our present knowledge of the empirical parameters if dUrca is always (up to $2M_\odot$) forbidden, but this is hardly the case if very massive NS can cool via dUrca; and finally, the most important empirical parameters which are still affected by large uncertainties and play an important role in determining the radius of neutrons stars are the slope and curvature of the symmetry energy ($L_{sym}$ and $K_{sym}$) as well as the skewness parameters ($Q_{sat/sym}$).