Gravitational-wave constraints on the neutron-star-matter Equation of State

TL;DR

This paper uses gravitational wave data from neutron-star mergers to significantly constrain the neutron-star matter equation of state, limiting possible stellar radii and deformabilities.

Contribution

It introduces a method to generate neutron-star EoSs consistent with gravitational wave and mass observations, reducing the range of viable models.

Findings

Maximum radius of a 1.4 solar-mass neutron star is 13.6 km

Smallest allowed tidal deformability for a 1.4 solar-mass star is 120

Constraints dramatically narrow the range of possible EoSs

Abstract

The LIGO/Virgo detection of gravitational waves originating from a neutron-star merger, GW170817, has recently provided new stringent limits on the tidal deformabilities of the stars involved in the collision. Combining this measurement with the existence of two-solar-mass stars, we generate a generic family of neutron-star-matter Equations of State (EoSs) that interpolate between state-of-the-art theoretical results at low and high baryon density. Comparing the results to ones obtained without the tidal-deformability constraint, we witness a dramatic reduction in the family of allowed EoSs. Based on our analysis, we conclude that the maximal radius of a 1.4-solar-mass neutron star is 13.6 km, and that smallest allowed tidal deformability of a similar-mass star is $\Lambda(1.4 M_\odot) = 120$.