Mixed neutron-star-plus-wormhole systems: Linear stability analysis

TL;DR

This paper investigates neutron star-wormhole systems with ghost scalar fields, finding static solutions but demonstrating their linear instability, thus questioning their potential astrophysical viability.

Contribution

It introduces a model of neutron star-wormhole configurations with a ghost scalar field and performs a linear stability analysis of these solutions.

Findings

Static solutions are found for the systems.

The solutions are linearly unstable.

Implications for astrophysical relevance are discussed.

Abstract

We consider configurations consisting of a neutron star with a wormhole at the core. The wormhole is held open by a ghost scalar field with a quartic coupling. The neutron matter is described by a perfect fluid with a polytropic equation of state. We obtain static regular solutions for these systems. A stability analysis, however, shows that they are unstable with respect to linear perturbations.