Towards a better understanding of dense matter from recent neutron-star observations

It is only very recently that neutron star (NS) observations have started to provide tight constraints on the dense matter equation of state (EoS): pressure, energy density, phase transition and composition, etc. I will present a few of them, such as the thermal emission from the surface of NS and the tidal deformability from binary NS merger GW170817. I will also present a semi-agnostic approach for the EoS employed for such analyses. The knowledge on the EoS can be analyzed in terms of the nuclear empirical parameters, a few of which are known from nuclear experiments. I will show how the confrontation with astrophysical observations could provide additional information on these parameters, such as the curvature of the symmetry energy Ksym. A discussion of the origin of some correlations among these empirical parameters, as well as of the role of the unknown parameters on these correlations will also be presented. I will conclude with preliminary results confronting some nuclear and astrophysical constraints which could potentially shed light on the presence of phase transitions in the core of NS.