Neutron Star Observations: Prognosis for Equation of State Constraints
  We investigate how current and proposed observations of neutron stars can lead to an understanding of the state of their interiors and the key unknowns: the typical neutron star radius and the neutron star maximum mass. A theoretical analysis of neutron star structure, including general relativistic limits to mass, compactness, and spin rates is made. We consider observations made not only with photons, ranging from radio waves to X-rays, but also those involving neutrinos and gravity waves. We detail how precision determinations of structural properties would lead to significant restrictions on the poorly understood equation of state near and beyond the equilibrium density of nuclear matter. 
James M. Lattimer, Maddapa Prakash