Black holes and wormholes subject to conformal mappings

TL;DR

This paper explores how solutions in gravity theories with conformal frames can appear as wormholes in one frame and horizonless geometries in another, highlighting the impact of conformal mappings on spacetime interpretation.

Contribution

It demonstrates the transformation of Brans class IV solutions between conformal frames and explains the underlying reasons for their differing geometrical features.

Findings

Brans class IV solutions can represent wormholes in the Jordan frame.

The same solutions correspond to horizonless geometries in the Einstein frame.

Conformal mappings can significantly alter the physical interpretation of gravitational solutions.

Abstract

Solutions of the field equations of theories of gravity which admit distinct conformal frame representations can look very different in these frames. We show that Brans class IV solutions describe wormholes in the Jordan frame (in a certain parameter range) but correspond to horizonless geometries in the Einstein frame. The reasons for such a change of behaviour under conformal mappings are elucidated in general, using Brans IV solutions as an example.