350 research outputs found
Holographic Superconductors with Lifshitz Scaling
Black holes in asymptotically Lifshitz spacetime provide a window onto finite
temperature effects in strongly coupled Lifshitz models. We add a Maxwell gauge
field and charged matter to a recently proposed gravity dual of 2+1 dimensional
Lifshitz theory. This gives rise to charged black holes with scalar hair, which
correspond to the superconducting phase of holographic superconductors with z >
1 Lifshitz scaling. Along the way we analyze the global geometry of static,
asymptotically Lifshitz black holes at arbitrary critical exponent z > 1. In
all known exact solutions there is a null curvature singularity in the black
hole region, and, by a general argument, the same applies to generic Lifshitz
black holes.Comment: 23 pages, 4 figures; v2: added references; v3: matches published
versio
String Thermalization at a Black Hole Horizon
Susskind has recently shown that a relativistic string approaching the event
horizon of a black hole spreads in both the transverse and longitudinal
directions in the reference frame of an outside observer. The transverse
spreading can be described as a branching diffusion of wee string bits. This
stochastic process provides a mechanism for thermalizing the quantum state of
the string as it spreads across the stretched horizon.Comment: 14 pages, latex, SU-ITP-94-4, NSF-ITP-94-1
Constructing a counterexample to the black hole complementarity
We propose a regular black hole whose inside generates a de Sitter space and
then is finally frustrated into a singularity. It is a modified model which was
suggested originally by Frolov, Markov, and Mukhanov. In our model, we could
adjust a regular black hole so that its period before going into the extreme
state is much longer than the information retention time. During this period an
observer could exist who observes the information of the Hawking radiation,
falls freely into the regular center of the black hole, and finally meets the
free-falling information again. The existence of such an observer implies that
the complementary view may not be consistent with a regular black hole, and
therefore, is not appropriate as a generic principle of black hole physics.Comment: 8 pages, 5 figure
AdS/CFT and the Information Paradox
The information paradox in the quantum evolution of black holes is studied
within the framework of the AdS/CFT correspondence. The unitarity of the CFT
strongly suggests that all information about an initial state that forms a
black hole is returned in the Hawking radiation. The CFT dynamics implies an
information retention time of order the black hole lifetime. This fact
determines many qualitative properties of the non-local effects that must show
up in a semi-classical effective theory in the bulk. We argue that no
violations of causality are apparent to local observers, but the semi-classical
theory in the bulk duplicates degrees of freedom inside and outside the event
horizon. Non-local quantum effects are required to eliminate this redundancy.
This leads to a breakdown of the usual classical-quantum correspondence
principle in Lorentzian black hole spacetimes.Comment: 16 pages, harvmac, reference added, minor correction
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