Wormholes Threaded by Chiral Fields

TL;DR

This paper studies Lorentzian wormholes with phantom and chiral matter fields, revealing how increasing gravitational coupling alters their geometry from single to double throats and analyzing their stability.

Contribution

It introduces a detailed analysis of wormholes threaded by chiral fields, including the geometric transition and stability properties, extending previous models with new matter field interactions.

Findings

Wormholes evolve from single to double throats with increased coupling.

Maximum coupling causes throats to pinch off, forming a closed universe.

All such wormholes are found to be unstable.

Abstract

We consider Lorentzian wormholes with a phantom field and chiral matter fields. The chiral fields are described by the non-linear sigma model with or without a Skyrme term. When the gravitational coupling of the chiral fields is increased, the wormhole geometry changes. The single throat is replaced by a double throat with a belly inbetween. For a maximal value of the coupling, the radii of both throats reach zero. Then the interior part pinches off, leaving a closed universe and two (asymptotically) flat spaces. A stability analysis shows that all wormholes threaded by chiral fields inherit the instability of the Ellis wormhole.