A paucity of bulk entangling surfaces: AdS wormholes with de Sitter interiors

Understand

We study and construct spacetimes, dubbed planar AdS-dS-wormholes, satisfying the null energy condition and having two asymptotically AdS boundaries connected through a (non-traversable) inflating wormhole.

• As for other wormholes, it is natural to expect dual descriptions in terms of two disconnected CFTs in appropriate entangled states.
• But for our cases certain expected bulk entangling surfaces used by the Hubeny-Rangamani-Takayanagi (HRT) prescription to compute CFT entropy do not exist.
• In particular, no real codimension-2 extremal surface can run from one end of the wormhole to the other.