Traversable wormholes from massless conformally coupled scalar fields

TL;DR

This paper explores how massless conformally coupled scalar fields can produce traversable wormholes by violating energy conditions, presenting exact solutions that include known black holes, naked singularities, and wormholes.

Contribution

It introduces a three-parameter family of exact solutions coupling conformal scalar fields to gravity, revealing new traversable wormhole geometries.

Findings

Exact solutions include traversable wormholes, naked singularities, and Schwarzschild black holes.

The conformally coupled scalar field's stress-energy tensor violates the null energy condition.

Traversable wormholes are possible within classical scalar field theories without exotic matter.

Abstract

The massless conformally coupled scalar field is characterized by the so-called "new improved stress-energy tensor", which is capable of classically violating the null energy condition. When coupled to Einstein gravity we find a three-parameter class of exact solutions. These exact solutions include the Schwarzschild geometry, assorted naked singularities, and a large class of traversable wormholes.