Events

What assumptions are implicit in the “classic” Penrose diagram for an evaporating black hole? What are we allowed to draw on it without introducing contradictions or circular reasoning? We answer these questions by numerically evaluating Penrose diagrams for explicit models of evaporating black hole spacetimes, emphasizing physical details like energy condition violations, apparent horizons, local curvatures, and global hyperbolicity. We consider the implications of these details for questions of long term, evaporation time, and Page time unitarity, and for the stories we tell about black hole evaporation. If time permits we’ll also discuss one more major assumption in the diagram: the lack of spin and charge, and what changes this makes to the story.