Traversable wormholes inside anisotropic magnetized neutron stars: physical properties and potential observational imprints

TL;DR

This paper explores the theoretical existence of traversable wormholes within anisotropic, magnetized neutron stars, analyzing their physical properties and potential gravitational wave signatures that could be observed.

Contribution

It introduces a model of wormhole-neutron star systems supported by scalar fields, incorporating pressure anisotropy and magnetic fields, and examines their stability and observational features.

Findings

Wormholes remain traversable despite anisotropy and magnetic fields.

Such systems can have masses exceeding 8 solar masses and high surface redshifts.

Gravitational wave echo times vary with system parameters, offering potential observational signatures.

Abstract

In this paper, we formulate wormhole-plus-neutron-star (WH+NS) systems supported by two scalar fields, allowing for both pressure anisotropy of the neutron fluid and magnetic field. In general, such WH+NS systems contain ghosts; however, these ghosts can be eliminated. We find that the wormhole remains traversable regardless of whether anisotropy of the neutron fluid and/or magnetic fields are included. In particular, the null energy condition (NEC) remains violated in the vicinity of the wormhole throat, ensuring the traversable nature of the geometry. For magnetized configurations, the resulting WH+NS systems can become extremely massive, with ADM masses exceeding $8\,M_\odot$, and can exhibit large surface redshifts exceeding $z \simeq 1.5$. Furthermore, we analyze the gravitational-wave echo time of the systems, which serves as a potential observational imprint. Our results indicate that the echo time can vary depending on the fluid anisotropy and the magnetic field configuration, suggesting that WH+NS systems may provide distinctive signals of gravitational echo.