Neutron Star Equation of State in light of GW190814

TL;DR

This paper explores the possibility of heavy neutron stars consistent with GW190814 by modeling their internal structure with non-trivial speed of sound, predicting small tidal deformabilities that require advanced detectors for verification.

Contribution

It introduces a novel modeling approach for heavy neutron stars using non-trivial speed of sound profiles, challenging spectral methods and providing testable gravitational wave signatures.

Findings

Heavy neutron stars can have small Love numbers and quadrupole moments.

Detection of such stars requires a tenfold increase in gravitational wave sensitivity.

Third generation detectors could potentially observe these heavy neutron stars.

Abstract

The observation of gravitational waves from an asymmetric binary opens the possibility for heavy neutron stars, but these pose challenges to models of the neutron star equation of state. We construct heavy neutron stars by introducing non-trivial structure in the speed of sound sourced by deconfined QCD matter, which cannot be well recovered by spectral representations. Their moment of inertia, Love number and quadrupole moment are very small, so a tenfold increase in sensitivity may be needed to test this possibility with gravitational waves, which is feasible with third generation detectors.