The Campanelli-Lousto and veiled spacetimes

TL;DR

This paper reexamines the Campanelli-Lousto solutions in Brans-Dicke theory, revealing they can represent wormholes or naked singularities depending on parameters, and discusses implications for conformal transformations in spacetime interpretations.

Contribution

It clarifies the physical nature of Campanelli-Lousto solutions and explores their conformal counterparts, highlighting caution in interpreting conformally related spacetimes.

Findings

Campanelli-Lousto solutions can describe wormholes or naked singularities.

The veiled Schwarzschild metric is a special case of the CL metric.

Conformal transformations can alter the physical interpretation of solutions.

Abstract

The Campanelli-Lousto solutions of Brans-Dicke theory, usually reported as black holes are reconsidered and shown to describe, according to the values of a parameter, wormholes or naked singularities. The veiled Schwarzschild metric recently used as an example to discuss conformal frames and their equivalence corresponds to a special case of the CL metric. The conformal cousins of these solutions, and of the Riegert black hole solution of conformally invariant Weyl theory, are analysed, leading to a word of caution when interpreting physically spacetimes generated via conformal transformations from known seed solutions.