An Entropy-Area Law for Neutron Stars Near the Black Hole Threshold

Understand

Neutron stars exhibit a set of universal relations independent of their equation of state that bears semblance to the black hole no hair relations.

• Motivated by this, we analytically and numerically explore other relations that connect neutron star and black hole universality.
• By analyzing two different measures, we find that certain rescaled entropies possess a nearly universal behavior.
• We also discover that when the compactness of neutron stars approaches the black hole limit, the rescaled entropy approaches that of a black hole, and the thermodynamic entropy scales with the stellar surface area in an ever more universal way.