"We argue that the following three statements cannot all be true: (i) Hawking radiation is in a pure state, (ii) the information carried by the radiation is emitted
h low energy effective field theory valid beyond some microscopic distance from the horizon, and (iii) the infalling observer encounters
nothing unusual at the horizon. Perhaps the most conservative resolution is that the infalling observer burns up at the horizon. Alternatives would seem to require
novel dynamics that nevertheless cause notable violations of semiclassical physics at macroscopic distances from the horizon."
Black Holes: Complementarity or Firewalls?
Ahmed Almheiri,1* Donald Marolf,2*y Joseph Polchinski,3y and James Sully4*
*Department of Physics
University of California
Santa Barbara, CA 93106
We are outside objective black hole horizons whose Penrose diagram (no rotation) is
In contrast we are inside our subjective past and future cosmological horizons that form the causal diamond.
Hawking & Gibbons show that Bekenstein-Unruh thermodynamics applies in both cases. So does Tamara Davis's PhD (2004 Univ New South Wales).
However, in terms of Black Hole Complementarity the two situations are qualitatively different.
(iii) must be true for our cosmological future event horizon because the latter is subjective relative to us in an undivided whole (Cramer transaction)
(iii) is essentially the Einstein Equivalence Principle
(iii) however need not be true for the LIF geodesic in-falling observer to an objective black hole horizon.
I think (ii) must be true in both cases.