Black hole and wormhole solutions in Einstein-Maxwell-Scalar theory

TL;DR

This paper classifies and analyzes charged black hole and wormhole solutions within Einstein-Maxwell-Scalar theory, highlighting their properties and differences between conformal frames, with implications for scalar-tensor theories.

Contribution

It provides a comprehensive classification of black hole and wormhole solutions in Einstein-Maxwell-Scalar theory, including their properties and frame-dependent features.

Findings

Existence of specific black hole solutions with infinite surface horizons

Presence of wormholes and naked singularities under certain conditions

Differences between Einstein and non-minimal coupling frames

Abstract

We classified and studied the charged black hole and wormhole solutions in the Einstein--Maxwell system in the presence of a massless, real scalar field. The possible existence of charged black holes in general scalar--tensor theories was studied in {Bronnikov et al, 1999;} black holes and wormholes exist for a negative kinetic term for the scalar field. Using a conformal transformation, the static, spherically symmetric possible structures in the minimal coupled system are described. Besides wormholes and naked singularities, only a restricted class of black hole exists, exhibiting a horizon with an infinite surface and a timelike central singularity. The black holes and wormholes defined in the Einstein frame have some specificities with respect to the non-minimal coupling original frame, which are discussed in the text.