Perturbative QCD and the neutron star equation of state

We construct a physics-agnostic approach to the neutron star (NS) equation of state (EoS) based on sound speed model, which connects both low-density information from nuclear theory and high-density constraints perturbative quantum chromodynamics (pQCD). Using this approach, we study impact pQCD calculations NS EoS that have been constrained by astrophysical observations. find affects mainly beyond densities realized in NS. Furthermore, observe an interesting interplay between constraints, with preferring softer for heaviest while recent NICER observations suggest be stiffer. explore sensitivity our findings uncertainties constraining power if future heavy were radii larger than 13 km.