Donald Marolf

Black holes: complementarity or firewalls?

A bstractWe 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 from the region near the horizon, with 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.

An apologia for firewalls

A bstractWe address claimed alternatives to the black hole firewall. We show that embedding the interior Hilbert space of an old black hole into the Hilbert space of the early radiation is inconsistent, as is embedding the semi-classical interior of an AdS black hole into any dual CFT Hilbert space. We develop the use of large AdS black holes as a system to sharpen the firewall argument. We also reiterate arguments that unitary non-local theories can avoid firewalls only if the non-localities are suitably dramatic.

Bulk and transhorizon measurements in AdS/CFT

A bstractWe discuss the construction of bulk operators in asymptotically AdS space-times, including the interiors of AdS black holes. We use this to address the question “If Schrodinger’s cat were behind the horizon of an AdS black hole, could we determine its state by a measurement in the dual CFT?” We argue that the answer is affirmative, but this assumes a complete knowledge of both the bulk and boundary dynamics.

On geodesic propagators and black hole holography

One of the most challenging technical aspects of the dualities between string theory on anti--de Sitter spaces and conformal field theories is understanding how location in the interior of spacetime is represented in the field theory. It has recently been argued that the interior of the spacetime can be directly probed by using intrinsically non-local quantities in the field theory. In addition, Balasubramanian and Ross [Phys. Rev. D 61, 044009 (2000)] argued that when the spacetime described the formation of an

On the support of the Ashtekar-Lewandowski measure

{\mathrm{AdS}}_{3}

Actions and fermionic symmetries for D-branes in bosonic backgrounds

black hole, the propagator in the field theory probed the whole spacetime, including the region behind the horizon. We use the same approach to study the propagator for the BTZ black hole and a black hole solution with a single exterior region, and show that it reproduces the propagator associated with the natural vacuum states on these spacetimes. We compare our result with a toy model of the CFT for the single-exterior black hole, finding remarkable agreement. The spacetimes studied in this work are analytic, which makes them quite special. We also discuss the interpretation of this propagator in more general spacetimes, shedding light on certain issues involving causality, black hole horizons, and products of local operators on the boundary.

A new approach to string cosmology

AbstractWe show that the Ashtekar-Isham extension

Single exterior black holes and the AdS / CFT conjecture

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