2,105 research outputs found
Typical Event Horizons in AdS/CFT
We consider the construction of local bulk operators in a black hole
background dual to a pure state in conformal field theory. The properties of
these operators in a microcanonical ensemble are studied. It has been argued in
the literature that typical states in such an ensemble contain firewalls, or
otherwise singular horizons. We argue this conclusion can be avoided with a
proper definition of the interior operators.Comment: 8 pages, 2 figures. arXiv admin note: text overlap with
arXiv:1310.799
Firewalls in AdS/CFT
Several recent papers argue against firewalls by relaxing the requirement for
locality outside the stretched horizon. In the firewall argument, locality
essentially serves the purpose of ensuring that the degrees of freedom required
for infall are those in the proximity of the black hole and not the ones in the
early radiation. We make the firewall argument sharper by utilizing the AdS/CFT
framework and claim that the firewall argument essentially states that the dual
to a thermal state in the CFT is a firewall.Comment: 11 pages plus references, 8 figures; version accepted for publication
in JHE
Soft Black Hole Absorption Rates as Conservation Laws
The absorption rate of low-energy, or soft, electromagnetic radiation by
spherically symmetric black holes in arbitrary dimensions is shown to be fixed
by conservation of energy and large gauge transformations. We interpret this
result as the explicit realization of the Hawking-Perry-Strominger Ward
identity for large gauge transformations in the background of a non-evaporating
black hole. Along the way we rederive and extend previous analytic results
regarding the absorption rate for the minimal scalar and the photon.Comment: 20 Pages, 1 figur
Unitarity and fuzzball complementarity: "Alice fuzzes but may not even know it!"
We investigate the recent black hole firewall argument. For a black hole in a
typical state we argue that unitarity requires every quantum of radiation
leaving the black hole to carry information about the initial state. An
information-free horizon is thus inconsistent with unitary at every step of the
evaporation process (in particular both before and after Page time). The
required horizon-scale structure is manifest in the fuzzball proposal which
provides a mechanism for holding up the structure. In this context we want to
address the experience of an infalling observer and discuss the recent fuzzball
complementarity proposal. Unlike black hole complementarity and observer
complementarity which postulate asymptotic observers experience a hot membrane
while infalling ones pass freely through the horizon, fuzzball complementarity
postulates that fine-grained operators experience the details of the fuzzball
microstate and coarse-grained operators experience the black hole. In
particular, this implies that an infalling detector tuned to energy E ~ T,
where T is the asymptotic Hawking temperature, does not experience free infall
while one tuned to E >> T does.Comment: v3: 33 pages + citations, 8 figures, version accepted for publicatio
An sl(2, R) current algebra from AdS_3 gravity
We provide a set of chiral boundary conditions for three-dimensional gravity
that allow for asymptotic symmetries identical to those of two-dimensional
induced gravity in light-cone gauge considered by Polyakov. These are the most
general boundary conditions consistent with the boundary terms introduced by
Compere, Song and Strominger recently. We show that the asymptotic symmetry
algebra of our boundary conditions is an sl(2,R) current algebra with level
given by c/6. The fully non-linear solution in Fefferman--Graham coordinates is
also provided along with its charges.Comment: 8 page
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