Revisiting the Brans solutions of scalar-tensor gravity

TL;DR

This paper re-examines the Brans solutions in scalar-tensor gravity, clarifying their nature as wormholes or naked singularities rather than black holes across different parameter ranges.

Contribution

It provides a detailed analysis of the static, spherically symmetric Brans solutions in both conformal frames, resolving contradictions in previous literature.

Findings

Solutions describe wormholes or naked singularities, not black holes

Analysis in both Jordan and Einstein frames confirms the nature of solutions

Parameter ranges determine the geometric structure of solutions

Abstract

Motivated by statements in the literature which contradict two general theorems, the static and spherically symmetric Brans solutions of scalar-tensor gravity are analyzed explicitly in both the Jordan and the Einstein conformal frames. Depending on the parameter range, these solutions describe wormholes or naked singularities but not black holes.