Making near-extremal wormholes traversable

Understand

We construct a traversable wormhole from a charged AdS black hole by adding a coupling between the two boundary theories.

• We investigate how the effect of this deformation behaves in the extremal limit of the black hole.
• The black holes have finite entropy but an infinitely long throat in the extremal limit.
• We argue that it is still possible to make the throat traversable even in the extremal limit, but this requires either tuning the field for which we add a boundary coupling close to an instability threshold or scaling the strength of the coupling inversely with the temperature.