Source of black bounces in general relativity

TL;DR

This paper derives the matter content responsible for black bounce solutions in general relativity, showing they involve phantom scalar fields coupled with nonlinear electrodynamics, and analyzes associated energy conditions.

Contribution

It introduces a general method to determine matter sources for black bounce solutions, applied to specific models, revealing the role of phantom scalar fields and energy condition violations.

Findings

Black bounce solutions are supported by phantom scalar fields.

The models violate null energy conditions.

Solutions involve nonlinear electrodynamics coupling.

Abstract

Black bounces are spacetimes that can describe, depending on certain parameters, black holes or wormholes. In this work, we use a method to obtain the matter content that generates black bounce solutions in general relativity. The method is constructed in a general way, and as models, we apply it to the Simpson--Visser black bounce solution and the Bardeen-type black bounce solution. We obtain that these metrics are solutions of Einstein's equations when we consider the coupling of the gravitational interaction with a phantom scalar field with a nonlinear electrodynamics. The presence of the phantom scalar field is linked to the fact that this type of solution violates the null energy condition. We analyze separately the energy conditions associated with the stress-energy tensor for the scalar field and for the electromagnetic field.