Exact rotating wormholes via Ehlers transformations

TL;DR

This paper constructs exact rotating wormhole solutions in Einstein-Maxwell theory using Ehlers transformations, revealing new geometries with ergoregions and potential stability benefits from slow rotation.

Contribution

It introduces two novel rotating wormhole geometries derived from a static seed using Ernst's method, expanding the set of exact solutions in gravitational physics.

Findings

Construction of rotating wormholes embedded in rotating and magnetic backgrounds

Identification of ergoregions in the new rotating geometries

Potential stabilization of wormholes through slow rotation

Abstract

In this paper, we construct exact rotating wormholes using Ehlers solution-generating technique. This is based on the Ernst description of four-dimensional, stationary, and axially symmetric solutions of the Einstein-Maxwell theory. We adopt the static Barcel\'o-Visser wormhole derived from the Einstein-Maxwell-conformal-scalar theory as a seed, and demonstrate, through the Ernst approach, how to construct two novel geometries of rotating wormholes. These geometries correspond to the Barcel\'o-Visser wormhole embedded within a rotating and a magnetic background, respectively. In the first case, the rotation is a result of a dragging force (due to the rotating background) acting on the initial static wormhole, while in the second case it is caused by the electromagnetic interaction between the electric charge of the static wormhole and the external magnetic field. We conduct a comprehensive analysis of the geometric properties of these configurations, and examine the new features introduced by rotation, such as the emergence of ergoregions. Recent evidence suggests that incorporating slow rotation can stabilise wormholes, rendering these exact, fully rotating solutions particularly appealing.