1,000 research outputs found
Microscopic derivation of the Bekenstein-Hawking entropy formula for non-extremal black holes
We derive the Bekenstein-Hawking entropy formula for four and five
dimensional non-supersymmetric black holes (which include the Schwarzchild
ones) by counting microscopic states. This is achieved by first showing that
these black holes are U-dual to the three-dimensional black hole of
Banados-Teitelboim-Zanelli and then counting microscopic states of the latter
following Carlip's approach. Higher than five dimensional black holes are also
considered. We discuss the connection of our approach to the D-brane picture.Comment: Misprints corrected, discussion section expanded, some references
added. Version to appear in Nucl. Phys. B. 29 pages, late
Holography and Infrared Conformality in Two Dimensions
This is a very brief review of some results from hep-th/0112154 and
hep-th/0209191. In holographic renormalization, we studied the RG flow of a 2d
N=(4,4) CFT perturbed by a relevant operator, flowing to a conformal fixed
point in the IR. Here, the supergravity dual is displayed, and the computation
of correlators is discussed. The sample stress-energy correlator given here
provides an opportunity to explicitly compare Zamolodchikov's C-function to the
proposal for a "holographic C-function".Comment: 4 pages, 1 figure, using cargese.cls (included). Proceedings of
Cargese ASI, "Progress in String, Field and Particle Theory", June-July 200
Holographic Construction of Excited CFT States
We present a systematic construction of bulk solutions that are dual to CFT
excited states. The bulk solution is constructed perturbatively in bulk fields.
The linearised solution is universal and depends only on the conformal
dimension of the primary operator that is associated with the state via the
operator-state correspondence, while higher order terms depend on detailed
properties of the operator, such as its OPE with itself and generally involve
many bulk fields. We illustrate the discussion with the holographic
construction of the universal part of the solution for states of two
dimensional CFTs, either on or on . We compute the
1-point function both in the CFT and in the bulk, finding exact agreement. We
comment on the relation with other reconstruction approaches.Comment: 26 pages, 4 figures, v2: comments adde
Hidden supersymmetry of domain walls and cosmologies
We show that all domain-wall solutions of gravity coupled to scalar fields
for which the worldvolume geometry is Minkowski or anti-de Sitter admit Killing
spinors, and satisfy corresponding first-order equations involving a
superpotential determined by the solution. By analytic continuation, all flat
or closed FLRW cosmologies are shown to satisfy similar first-order equations
arising from the existence of ``pseudo-Killing'' spinors.Comment: 4 pages, v2:minor improvements, refs added, version to appear in PR
Fuzzball solutions and D1-D5 microstates
We revisit the relation between fuzzball solutions and D1-D5 microstates. A consequence of the fact that the RR ground states (in the usual basis) are eigenstates of the R-charge is that only neutral operators can have non-vanishing expectation values on these states. We compute the holographic 1-point functions of the fuzzball solutions and find that charged chiral primaries have non-zero expectation values, except when the curve characterizing the solution is circular. The non-zero vevs reflect the fact that a generic curve breaks R-symmetry completely. This implies that fuzzball solutions (excepting circular ones) can only correspond to superpositions of RR states. We construct new solutions by appropriately superimposing fuzzball solutions that have vanishing vevs for all charged chiral primary operators and can therefore correspond to D1-D5 microstates
Branes in the plane wave background with gauge field condensates
Supersymmetric branes in the plane wave background with additional constant
magnetic fields are studied from the world-sheet point of view. It is found
that in contradistinction to flat space, boundary condensates on some maximally
supersymmetric branes necessarily break at least some supersymmetries. The
maximally supersymmetric cases with condensates are shown to be in one to one
correspondence with the previously classified class II branes.Comment: LaTeX, 31 pages, no figures; v2: references added, some typos
correcte
Holographic Coulomb branch vevs
We compute holographically the vevs of all chiral primary operators for
supergravity solutions corresponding to the Coulomb branch of N=4 SYM and find
exact agreement with the corresponding field theory computation. Using the
dictionary between 10d geometries and field theory developed to extract these
vevs, we propose a gravity dual of a half supersymmetric deformation of N=4 SYM
by certain irrelevant operators.Comment: 16 pages, v2 corrections in appendi
Properties of branes in curved spacetimes
A generic property of curved manifolds is the existence of focal points. We
show that branes located at focal points of the geometry satisfy special
properties. Examples of backgrounds to which our discussion applies are AdS_m x
S^n and plane wave backgrounds. As an example, we show that a pair of AdS_2
branes located at the north and south pole of the S^5 in AdS_5 x S^5 are half
supersymmetric and that they are dual to a two-monopole solution of N=4 SU(N)
SYM theory. Our second example involves spacelike branes in the (Lorentzian)
plane wave. We develop a modified lightcone gauge for the open string channel,
analyze in detail the cylinder diagram and establish open-closed duality. When
the branes are located at focal points of the geometry the amplitude acquires
most of the characteristics of flat space amplitudes. In the open string
channel the special properties are due to stringy modes that become massless.Comment: 41 pages; v2:typos corrected, ref adde
Pseudo-Supersymmetry and the Domain-Wall/Cosmology Correspondence
The correspondence between domain-wall and cosmological solutions of gravity
coupled to scalar fields is explained. Any domain wall solution that admits a
Killing spinor is shown to correspond to a cosmology that admits a
pseudo-Killing spinor: whereas the Killing spinor obeys a Dirac-type equation
with hermitian `mass'-matrix, the corresponding pseudo-Killing spinor obeys a
Dirac-type equation with a anti-hermitian `mass'-matrix. We comment on some
implications of (pseudo)supersymmetry.Comment: 11 pages, contribution to the proceedings of IRGAC 2006;v3: minor
change
The Holographic Universe
We present a holographic description of four-dimensional single-scalar
inflationary universes in terms of a three-dimensional quantum field theory.
The holographic description correctly reproduces standard inflationary
predictions in their regime of applicability. In the opposite case, wherein
gravity is strongly coupled at early times, we propose a holographic
description in terms of perturbative QFT and present models capable of
satisfying the current observational constraints while exhibiting a
phenomenology distinct from standard inflation. This provides a qualitatively
new method for generating a nearly scale-invariant spectrum of primordial
cosmological perturbations.Comment: 20 pages, 5 figs; extended version of arXiv:0907.5542 including
background material and detailed derivations. To appear in Proceedings of 1st
Mediterranean Conference on Classical and Quantum Gravit
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