Veronica Sacchi, "A generalisation of the Black Hole area theorem with index form methods"

Wednesday 18 Oct 2023, 16:00 → 17:00 Europe/Rome

2G26

Hawking’s black hole area theorem is in tension with the notorious phenomena of Hawking radiation. The key is that the former only holds within a classical regime, as it requires the null energy condition (NEC), a pointwise condition on the stress-energy tensor violated by quantum fields. After briefly reviewing the state of the art of energy conditions' proposals, I aim to present a proof of a generalised form of the black hole area theorem, starting from an averaged energy condition. In general, this form of the theorem allows for horizon decrease, but bounds from below the variation of its area. It will then become clear that not just any violation of NEC is enough to provide black hole evaporation, and we will see what is the weakest condition that forbids it. Time permitting, we will discuss two toy-models examples, where a full computation of the bound on the horizon decrease is possible, and we will compare it to the black hole evaporation rate.