Remote Nordic HET seminar: Nava Gaddam

Speaker: Nava Gaddam

Title: The black hole eikonal and the information paradox

Abstract: In this talk, I will show that there is a remarkable phase of quantum gravity (which we will call the 'black hole eikonal' phase in contrast to the flat space eikonal phase). It is defined by gravitational collisions near the horizon, and dominated by centre of mass energies E >> \gamma M_Pl, with \gamma = M_Pl/M_BH. This regime captures gravitational scattering with impact parameters smaller than the Schwarzschild radius. Scattering amplitudes are unitary suggesting a resolution of the information paradox; I will sketch the explicit derivation of the 2-2 amplitude for massless scalars, non-perturbatively in \gamma. Owing to the low energies of collisions, there are no firewalls experienced by infalling observers. A consequence of these results is that the information paradox is an emergent one at low energies and does not require detailed ultra-violet physics for a resolution.