GW170817: constraining the nuclear matter equation of state from the neutron star tidal deformability

TL;DR

This paper uses gravitational wave data from GW170817 to constrain the nuclear matter equation of state by analyzing neutron star tidal deformability and its relation to nuclear matter parameters, refining neutron star radius estimates.

Contribution

It demonstrates strong correlations between tidal deformability and specific nuclear matter parameters, providing tighter bounds on the EoS and neutron star radius.

Findings

Tidal deformability correlates with nuclear matter parameters.

Neutron star radius for 1.4 solar masses is constrained between 11.82 and 13.72 km.

GW170817 data constrains nuclear EoS parameters.

Abstract

Constraints set on key parameters of the nuclear matter equation of state (EoS) by the values of the tidal deformability, inferred from GW170817, are examined by using a diverse set of relativistic and non-relativistic mean field models. These models are consistent with bulk properties of finite nuclei as well as with the observed lower bound on the maximum mass of neutron star $\sim 2 ~ {\rm M}_\odot$. The tidal deformability shows a strong correlation with specific linear combinations of the isoscalar and isovector nuclear matter parameters associated with the EoS. Such correlations suggest that a precise value of the tidal deformability can put tight bounds on several EoS parameters, in particular, on the slope of the incompressibility and the curvature of the symmetry energy. The tidal deformability obtained from the GW170817 and its UV/optical/infrared counterpart sets the radius of a canonical $1.4~ {\rm M}_{\odot}$ neutron star to be $11.82\leqslant R_{1.4}\leqslant13.72$ km.