Going beyond ER=EPR in the SYK model

Understand

We discuss generalizations of the TFD to a density matrix on the doubled Hilbert space.

• We suggest that a semiclassical wormhole corresponds to a certain class of such density matrices, and specify how they are constructed.
• Different semi-classical profiles correspond to different non-overlapping density matrices.
• We show that this language allows for a finer criteria for when the wormhole is semiclassical, which goes beyond entanglement.