Speaker
Description
The composition of the core of neutron stars is still under debate. One possibility is that matter could be deconfined into quark matter due to the high densities reached in their cores. The possible existence of hadronic and hybrid stars is studied using microscopic models to describe the different phases of matter, including RMF models, chiral symmetric models, and quark models. Within these microscopic models, we aim to calculate the properties of neutron stars and nuclear matter and discuss the effect of different compositions of matter. The model parameters will be determined by Bayesian inference from neutron star observations, nuclear matter properties at saturation, and constraints from chiral effective field theory calculations of neutron matter and from pQCD calculations at very high densities. Several properties of neutron stars will be discussed: the maximum mass, the radius of the canonical NS, the speed of sound in the star, the proton fraction and the onset of the pn direct Urca processes, the transition to quark matter, the presence of hyperons. It will be shown that different compositions of neutron stars are compatible with current observational data. We will also discuss some effects on the neutron star properties due the presence of dark matter. The implications of possible information on the local derivatives from the mass-radius diagram in neutron star matter will be discussed. It is expected that the next generation of gravitational wave and electromagnetic detectors will allow the determination of the neutron star radius and mass with a small uncertainty, which will have an important impact on the information that can be extracted about the high density equation of state of baryonic matter.