TY - JOUR

T1 - Black hole evaporation and semiclassicality at large D

AU - Holdt-Sørensen, Frederik

AU - McGady, David A.

AU - Wintergerst, Nico

PY - 2020/7/15

Y1 - 2020/7/15

N2 - Black holes of sufficiently large initial radius are expected to be well described by a semiclassical analysis at least until half of their initial mass has evaporated away. For a small number of spacetime dimensions, this holds as long as the black hole is parametrically larger than the Planck length. In that case, curvatures are small, and backreaction onto geometry is expected to be well described by a time-dependent classical metric. We point out that at large D, small curvature is insufficient to guarantee a valid semiclassical description of black holes. Instead, the strongest bounds come from demanding that the rate of change of the geometry is small and that black holes scramble information faster than they evaporate. This is a consequence of the enormous power of Hawking radiation in D dimensions due to the large available phase space and the resulting minuscule evaporation times. Asymptotically, only black holes with entropies S >= DD+3 ogD are semiclassical. We comment on implications for realistic quantum gravity models in D

AB - Black holes of sufficiently large initial radius are expected to be well described by a semiclassical analysis at least until half of their initial mass has evaporated away. For a small number of spacetime dimensions, this holds as long as the black hole is parametrically larger than the Planck length. In that case, curvatures are small, and backreaction onto geometry is expected to be well described by a time-dependent classical metric. We point out that at large D, small curvature is insufficient to guarantee a valid semiclassical description of black holes. Instead, the strongest bounds come from demanding that the rate of change of the geometry is small and that black holes scramble information faster than they evaporate. This is a consequence of the enormous power of Hawking radiation in D dimensions due to the large available phase space and the resulting minuscule evaporation times. Asymptotically, only black holes with entropies S >= DD+3 ogD are semiclassical. We comment on implications for realistic quantum gravity models in D

KW - ENTROPY

KW - GRAVITY

U2 - 10.1103/PhysRevD.102.026016

DO - 10.1103/PhysRevD.102.026016

M3 - Journal article

VL - 102

JO - Physical Review D

JF - Physical Review D

SN - 2470-0010

IS - 2

M1 - 026016

ER -