http://arxiv.org/abs/2109.11571
Universal relations (i.e., insensitive to the equation of state) between macroscopic properties of neutron stars (NSs) have proven useful for a variety of applications — from providing a direct means to extract observables from data to breaking degeneracies that hinder tests of general relativity. Similarly, equation-of-state insensitive relations directly connecting macroscopic and microscopic properties of NSs can potentially provide a clean window into the behavior of nuclear matter. In this Letter, we uncover a tight correlation between certain macroscopic properties of NSs — its compactness, moment of inertia or tidal deformability — and the ratio of central pressure to central energy density, which can be interpreted as a mean notion of the stiffness of nuclear matter inside a NS. We describe interesting properties of this stiffness measure, quantify its universality, and explore its consequences in the face of recent NS observations.
J. Saes and R. Mendes
Mon, 27 Sep 21
34/68
Comments: 7 pages, 5 figures