Speaker
Description
In recent years it has become clear that in order to correctly interpret the many observables obtained for neutron stars (NS) such as their masses, radii and tidal deformabilities, one needs a better understanding of its equation of state at baryon densities of around 5 times the nuclear saturation density where a phase transition between hadronic and quark matter is also possible having characteristic thermodynamic properties. From a first-principle viewpoint, this represents a difficult task since most of the required central stellar densities immediately probe the nonperturbative sector of quantum chromodynamics (QCD) for which even today lattice QCD calculations are forbidden. Nevertheless, one can still resort to use ab initio results for the quark phase, in particular, cold and dense perturbative QCD, and study the non-trivial effects of short-range QCD interactions on superdense stars. In this talk I will discuss this impact on the structure and stability of several compact stars where interacting deconfined QCD matter might be present such as protoneutron stars, strange/charm stars, and hybrid NS with crossovers and discontinuous transitions for which in the latter case twin stars are also briefly discussed. Finally, I will present results for which instead of using general relativity and the standard model of particle physics when modeling quark stars, we now consider modified theories of gravity as well as adding the dark matter possibility, respectively.