A Negative Mode About Euclidean Wormhole

TL;DR

This paper investigates Euclidean wormholes in quantum gravity, finding a negative fluctuation mode that implies their contributions are imaginary, indicating an instability related to baby universe emission.

Contribution

It identifies a negative mode in the Giddings-Strominger wormhole, challenging the assumption of real contributions and suggesting a new interpretation involving universe instability.

Findings

Discovered a negative mode in the wormhole fluctuation spectrum.

Argued that wormhole contributions are purely imaginary.

Proposed wormholes indicate instability and baby universe emission.

Abstract

Wormholes -- solutions to the euclidean Einstein equations with non-trivial topology -- are usually assumed to make real contributions to amplitudes in quantum gravity. However, we find a negative mode among fluctuations about the Giddings-Strominger wormhole solution. Hence, the wormhole contribution to the euclidean functional integral is argued to be purely imaginary rather than real, which suggests the interpretation of the wormhole as describing the instability of a large universe against the emission of baby universes.