Constraints on the High-Density Nuclear Equation of State from Neutron   Star Observables
  Depending on the density reached in the cores of neutron stars, such objects may contain stable phases of novel matter found nowhere else in the Universe. This article gives a brief overview of these phases of matter and discusses astrophysical constraints on the high-density equation of state associated with ultra-dense nuclear matter. 
David Blaschke (Uniwersytet Wroclawski, Wroclaw, Poland & Bogoliubov   Laboratory for Theoretical Physics, JINR, Dubna, Russ...