Events

Is Black Hole Evaporation Prediction Friendly?

Manchak and Weatherall (2018) articulate a precise formulation of the black hole information paradox based upon the failure of predictability in black hole evaporation spacetimes. This failure is a consequence of the breakdown of global hyperbolicity. In this talk I offer a strategy for resolving this paradox. I first argue that failures of predictability in black hole evaporation are not well diagnosed by failures of global hyperbolicity, because describing black hole evaporation requires Planck-scale physics beyond the domain of applicability of general relativity. I then introduce novel spacetime properties: prediction and retrodiction friendliness, which plausibly diagnose failures of predictability which will not be fixed by a future theory of Planck-scale physics. I thus consider a formulation of the information paradox based on failures of retrodiction friendliness. However, deidealized models of black hole evaporation can be retrodiction friendly, and the viability of these retrodiction friendly spacetimes depends upon open questions in quantum gravity of which we are ignorant. It follows that there is no guarantee that black hole evaporation spacetimes are prediction or retrodiction unfriendly. Hence, the grounds for a paradox based upon failures of predictability, due to either non-global hyperbolicity or retrodiction unfriendliness, are dubious.

Monday, September 28, 2026 9:30 AM

Inperson
BHI Conference Room

Virtual
Zoom