Dynamic wormhole geometries in hybrid metric-Palatini gravity

TL;DR

This paper investigates the evolution of dynamic traversable wormholes within hybrid metric-Palatini gravity, demonstrating that certain solutions can satisfy energy conditions throughout their evolution.

Contribution

It introduces specific dynamic wormhole solutions in hybrid metric-Palatini gravity that meet energy conditions, expanding understanding of wormhole stability in modified gravity.

Findings

Some wormhole solutions satisfy null and weak energy conditions at all times.

Both barotropic and traceless energy-momentum configurations are compatible with evolving wormholes.

The study provides explicit models of dynamic wormholes in scalar-tensor hybrid gravity.

Abstract

In this work, we analyse the evolution of time-dependent traversable wormhole geometries in a Friedmann-Lema\^{i}tre-Robertson-Walker background in the context of the scalar-tensor representation of hybrid metric-Palatini gravity. We deduce the energy-momentum profile of the matter threading the wormhole spacetime in terms of the background quantities, the scalar field, the scale factor and the shape function, and find specific wormhole solutions by considering a barotropic equation of state for the background matter. We find that particular cases satisfy the null and weak energy conditions for all times. In addition to the barotropic equation of state, we also explore a specific evolving wormhole spacetime, by imposing a traceless energy-momentum tensor for the matter threading the wormhole and find that this geometry also satisfies the null and weak energy conditions at all times.