The black hole quantum atmosphere

Understand

Ever since the discovery of black hole evaporation, the region of origin of the radiated quanta has been a topic of debate.

• Recently it was argued by Giddings that the Hawking quanta originate from a region well outside the black hole horizon by calculating the effective radius of a radiating body via the Stefan--Boltzmann law.
• In this paper we try to further explore this issue and end up corroborating this claim, using both a heuristic argument and a detailed study of the stress energy tensor.
• We show that the Hawking quanta originate from what might be called a quantum atmosphere around the black hole with energy density and fluxes of particles peaked at about $4M$, running contrary to the popular belief that these originate from the ultra high energy excitations very close to the horizon.