A perturbative perspective on self-supporting wormholes

TL;DR

This paper introduces a perturbative approach to constructing self-supporting traversable wormholes by analyzing gravitational back-reaction effects of quantum fields, suggesting the possibility of eternal traversable wormholes in certain limits.

Contribution

It presents a new perturbative method for creating traversable wormholes that remain stable at late times, potentially leading to non-perturbative eternal wormholes.

Findings

Traversable wormholes can be induced by quantum back-reaction effects.

In extremal limits, wormholes remain traversable at late times.

The approach may simplify the construction of eternal traversable wormholes.

Abstract

We describe a class of wormholes that generically become traversable after incorporating gravitational back-reaction from linear quantum fields satisfying appropriate (periodic or anti-periodic) boundary conditions around a non-contractible cycle, but with natural boundary conditions at infinity (i.e., without additional boundary interactions). The class includes both asymptotically flat and asymptotically AdS examples. Simple asymptotically AdS$_3$ or asymptotically AdS$_3 \times S^1$ examples with a single periodic scalar field are then studied in detail. When the examples admit a smooth extremal limit, our perturbative analysis indicates the back-reacted wormhole remains traversable at later and later times as this limit is approached. This suggests that a fully non-perturbative treatment would find a self-supporting eternal traversable wormhole. While the general case remains to be analyzed in detail, the likely relation of the above effect to other known instabilities of extreme black holes may make the construction of eternal traversable wormholes more straightforward than previously expected.