Wormholes in Maximal Supergravity

Understand

In this brief note, we reconsider the problem of finding Euclidean wormhole solutions to maximal supergravity in d dimensions.

• We find that such solutions exists for all d less than or equal to 9.
• However, we argue that, in toroidally-compactified string theories, these saddle points never contribute to the path integral because of a tension with U-duality.