Lecture 24: Paradoxes for Large AdS Black Holes

In this lecture, we turned our attention to the information paradox for large AdS black holes. Large AdS black holes don't evaporate, so there is no information paradox in the usual sense. However, there is still an interesting question --- which arises from a conflict between unitarity and effective field theory --- which is as follows: "do generic AdS black holes have an empty interior that can be described holographically?"

This is the essence of all the recent discussion around the AMPSS papers.  It is clear that black holes in AdS formed from collapse do have an empty interior. But as we allow the black hole to evolve for a long time, or alternately if we pick a generic state using the Haar measure on the Hilbert space, do we still get a bulk geometry that corresponds to the classical AdS Schwarzschild black hole.

In this lecture, we described some paradoxes around this question, including the "lack of a left-inverse paradox", "the occupancy paradox" and the "N_a \neq 0" paradox.

Lecture 24 notes