The remnant of GW170817: a trapped neutron star with a hypermassive incompressible superfluid core

TL;DR

This paper models the GW170817 remnant as a hypermassive neutron star with a superfluid core, predicting its mass, radius, and evolution, and proposing it as a dark energy object and black hole candidate.

Contribution

It introduces a bimetric spacetime model for glitching pulsars and applies it to predict properties of the GW170817 remnant as a superfluid core neutron star.

Findings

Remnant mass between 2.8 and 3.351 solar masses

Predicted radius of 10.764 km

Remnant may evolve into a dark energy object

Abstract

Our bimetric spacetime model of glitching pulsars is applied to the remnant of GW170817. Accordingly, pulsars are born with embryonic incompressible superconducting gluon-quark superfluid cores (SuSu-matter) that are embedded in Minkowski spacetime, whereas the ambient compressible and dissipative media (CDM) are imbedded in curved spacetime. As pulsars cool down, the equilibrium between both spacetime is altered, thereby triggering the well-observed glitch phenomena. Based thereon and assuming all neutron stars (NSs) to be born with the same initial mass of $M_{NS}(t=0) \approx 1.25\,\mathcal{M}_{\odot},$ we argue that the remnant of GW170817 should be a relatively faint NS with a hypermassive central core made of SuSu-matter. The effective mass and radius of the remnant are predicted to be $[2.8 \mathcal{M}_{\odot} < \mathcal{M}_{rem} \le 3.351 \mathcal{M}_{\odot}]$ and $R_{rem}=10.764$ km, whereas the mass of the enclosed SuSu-core is $\mathcal{M}_{core}=1.7 \mathcal{M}_{\odot}.$ Here, about $1/2~ \mathcal{M}_{core}$ is an energy enhancement triggered by the phase transition of the gluon-quark-plasma from the microscopic into macroscopic scale. The current compactness of the remnant is $\alpha_c = 0.918,$ but predicted to increase as the CDM and cools down, rendering the remnant an invisible dark energy object, and therefore to an excellent black hole candidate.