Lecture 7: Resolving Hawking's original paradox
We concluded our discussion of Hawking's original paradox. Hawking original argument had two aspects. The first was a concrete computation of low-point correlators at future null infinity. We already explained why this was insufficient to conclude that the final state would be thermal.
But, in addition, Hawking argued that the external observer would have to adopt a "principle of ignorance" about the black hole interior and this is why the external observer would see a mixed state for the final radiation. In this lecture, we discussed several difficulties with such an assumption. We explained why we do not expect the no-hair theorem to generalize to quantum mechanics. Then we also discussed, from various perspectives, why it does not appear possible to change the black-hole interior without also changing the exterior in quantum gravity.
