252 research outputs found
Supersymmetric Kerr--anti-deSitter solutions
We prove the existence of one quarter supersymmetric type IIB configurations
that arise as non-trivial scaling solutions of the standard five dimensional
Kerr-AdS black holes by the explicit construction of its Killing spinors. This
neutral, spinning solution is asymptotic to the static anti-deSitter space-time
with cosmological constant , it has two finite
equal angular momenta , mass and a naked singularity.We also address the scaling limit
associated with one half supersymmetric solution with only one angular
momentum.Comment: 15 pages, no figure
Holography of 3d Flat Cosmological Horizons
We provide a first derivation of the Bekenstein-Hawking entropy of 3d flat
cosmological horizons in terms of the counting of states in a dual field
theory. These horizons appear in the shifted-boost orbifold of R^{1,2}, the
flat limit of non-extremal rotating BTZ black holes. These 3d geometries carry
non-zero charges under the asymptotic symmetry algebra of R^{1,2}, the 3d
Bondi-Metzner-Sachs (BMS3) algebra. The dual theory has the symmetries of the
2d Galilean Conformal Algebra, a contraction of two copies of the Virasoro
algebra, which is isomorphic to BMS3. We study flat holography as a limit of
AdS3/CFT2 to semi-classically compute the density of states in the dual,
exactly reproducing the bulk entropy in the limit of large charges. Our flat
horizons, remnants of the BTZ inner horizons also satisfy a first law of
thermodynamics. We comment on how the dual theory reproduces the bulk first law
and how cosmological bulk excitations are matched with boundary quantum
numbers.Comment: 5 pages; v2: Typos corrected, references update
A proposal for 3d quantum gravity and its bulk factorization
Recent progress in AdS/CFT has provided a good understanding of how the bulk
spacetime is encoded in the entanglement structure of the boundary CFT.
However, little is known about how spacetime emerges directly from the bulk
quantum theory. We address this question in an effective 3d quantum theory of
pure gravity, which describes the high temperature regime of a holographic CFT.
This theory can be viewed as a -deformation and dimensional uplift of JT
gravity. Using this model, we show that the Bekenstein-Hawking entropy of a
two-sided black hole equals the bulk entanglement entropy of gravitational edge
modes. In the conventional Chern-Simons description, these black holes
correspond to Wilson lines in representations of \PSL(2,\mathbb{R})\otimes
\PSL(2,\mathbb{R}) . We show that the correct calculation of gravitational
entropy suggests we should interpret the bulk theory as an extended topological
quantum field theory associated to the quantum semi-group
\SL^+_{q}(2,\mathbb{R})\otimes \SL^+_{q}(2,\mathbb{R}). Our calculation
suggests an effective description of bulk microstates in terms of collective,
anyonic degrees of freedom whose entanglement leads to the emergence of the
bulk spacetime.Comment: Appendix expanded. Discussion of extended TQFT is expanded and moved
to section 6. Added discussion of entropy formula in eq 4.2, comparison to
Liouville theory below eq 2.41, and expanded remarks on relation to
Teichmuller TQFT in section 6.4 and section
The Library of Babel
We show that heavy pure states of gravity can appear to be mixed states to
almost all probes. Our arguments are made for Schwarzschild black
holes using the field theory dual to string theory in such spacetimes. Our
results follow from applying information theoretic notions to field theory
operators capable of describing very heavy states in gravity. For certain
supersymmetric states of the theory, our account is exact: the microstates are
described in gravity by a spacetime ``foam'', the precise details of which are
invisible to almost all probes.Comment: 7 pages, 1 figure, Essay receiving honorable mention in the 2005
Gravity Research Foundation essay competitio
Brane-Intersection Dynamics from Branes in Brane Backgrounds
We derive the dynamics of M-brane intersections from the worldvolume action
of one brane in the background supergravity solution of another one. In this
way we obtain an effective action for the self-dual string boundary of an
M2-brane in an M5-brane, and show that the dynamics of the 3-brane intersection
of two M5-branes is described by a Dirac-Born-Infeld action.Comment: 12 pages,latex. Typos corrected, reference adde
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