Modified-gravity wormholes without exotic matter

TL;DR

This paper demonstrates that in modified gravity theories, wormholes can exist without exotic matter, as higher order curvature terms support the wormhole structure while matter satisfies all energy conditions.

Contribution

The work generalizes wormhole conditions in modified gravity, showing that exotic matter is not necessary for wormhole stability, unlike in classical general relativity.

Findings

Wormholes can be supported without exotic matter in modified gravity.

Higher order curvature terms act as a gravitational fluid supporting wormholes.

Matter threading the wormhole satisfies all classical energy conditions.

Abstract

A fundamental ingredient in wormhole physics is the flaring-out condition at the throat which, in classical general relativity, entails the violation of the null energy condition. In this work, we present the most general conditions in the context of modified gravity, in which the matter threading the wormhole throat satisfies all of the energy conditions, and it is the higher order curvature terms, which may be interpreted as a gravitational fluid, that support these nonstandard wormhole geometries. Thus, we explicitly show that wormhole geometries can be theoretically constructed without the presence of exotic matter, but are sustained in the context of modified gravity.