Traversable wormholes in beyond Horndeski theories

TL;DR

This paper constructs a broad class of explicit, asymptotically flat, regular wormhole solutions in higher order scalar-tensor theories without matter, using disformal transformations of seed black hole solutions from Horndeski theory.

Contribution

It introduces a method to generate explicit wormhole solutions in beyond Horndeski theories via disformal transformations, linking them to higher dimensional Lovelock origins.

Findings

Wormholes are vacuum solutions supported without matter.

Throat size and properties depend on coupling constants.

Solutions are parametrized by mass and theory-specific couplings.

Abstract

We construct a large class of explicit, asymptotically flat and regular wormhole solutions in higher order scalar tensor theories. The solutions are vacuum solutions of scalar tensor theory and no matter (exotic or regular) is introduced in order to support them. They are constructed via a general disformal transformation of a seed black hole solution. The seed solutions belong to a particular Horndeski theory which requires the presence of all extended Galileons and has a higher dimensional Lovelock origin. As a result, the resulting wormholes are always solutions of general beyond Horndeski theory. The particular class of wormholes we study are parametrised by their ADM mass and two coupling constants of the theory, one related to their higher dimensional Lovelock origin and one to the disformal transformation itself. The latter of the coupling constants affects the throat size of the wormhole solutions, thus giving them a compact or non-compact nature, as well as their properties.