11 research outputs found
Gravitino Propagator in anti de Sitter space
We construct the gauge invariant part of the propagator for the massless
gravitino in AdS(d+1) by coupling it to a conserved current. We also derive the
propagator for the massive gravitino.Comment: 24 pages; LaTe
AdS/CFT for Four-Point Amplitudes involving Gravitino Exchange
In this paper we compute the tree-level four-point scattering amplitude of
two dilatini and two axion-dilaton fields in type IIB supergravity in AdS5 x
S5. A special feature of this process is that there is an "exotic" channel in
which there are no singleparticle poles. Another novelty is that this process
involves the exchange of a bulk gravitino. The amplitude is interpreted in
terms of N = 4 supersymmetric Yang-Mills theory at large 't Hooft coupling.
Properties of the Operator Product Expansion are used to analyze the various
contributions from single- and double-trace operators in the weak and strongly
coupled regimes, and to determine the anomalous dimensions of semi-short
operators. The analysis is particularly clear in the exotic channel, given the
absence of BPS states.Comment: 32 pages, 1 figure. Published Version. Minor change
Four-point correlators with higher weight superconformal primaries in the AdS/CFT Correspondence
The four-point correlation function of two 1/2 BPS primaries of conformal
weight and two 1/2-BPS primaries of conformal weight is
calculated in the large 't Hooft, large limit. These operators are dual to
Kaluza-Klein supergravity fields with masses and .
Given that the existing formalism for evaluating sums of products of SO(6)
tensors that determine the effective couplings is only suitable for primaries
with small conformal dimensions, we make us of an alternative formalism based
on harmonic polynomials introduced by Dolan and Osborn.
We then show that the supergravity lagrangian relevant to the computation is
of sigma-model type (i.e., the four-derivative couplings vanish) and that the
final result for the connected amplitude splits into a free and an interacting
part, as expected on general grounds.Comment: 31 pages, 4 figure
Classical Integrability of the Squashed Three-sphere, Warped AdS3 and Schroedinger Spacetime via T-Duality
We discuss the integrability of 2d non-linear sigma models with target space
being the squashed three-sphere, warped anti-de Sitter space and the
Schroedinger spacetime. These models can be obtained via T-duality from
integrable models. We construct an infinite family of non-local conserved
charges from the T-dual Lax currents, enhancing the symmetry of warped anti-de
Sitter space and the Schroedinger spacetime to sl2(R)+sl2(R).Comment: 29 Pages, 3 appendices. Minor changes: added references, footnot
Next-next-to-extremal Four Point Functions of N=4 1/2 BPS Operators in the AdS/CFT Correspondence
Four point functions of general N=4 1/2-BPS primary fields, satisfying the
next-next-to-extremality condition
\Delta_{1}+\Delta_{2}+\Delta_{3}-\Delta_{4}=4 are studied at large N and strong
coupling. We apply new techniques to evaluate the effective couplings in
supergravity, and confirm that the four derivative couplings arising in the
five-dimensional supergravity vanish on-shell. We then show that the four point
amplitude resulting from supergravity naturally splits into a "free" and an
interactive part which resembles an effective quartic interaction. The precise
structure agrees with superconformal symmetry and supports the conjecture
formulated by Dolan, Osborn and Nirschl regarding the strongly coupled form of
four point correlators of chiral primary operators. We also evaluate the
amplitude in large N free field SYM theory and discuss the results in the
context of the correspondence.Comment: 40 pages, 6 figures, 6 appendices. Minor correction
Integrable Superstrings on the Squashed Three-sphere
In this note we study type II superstring theory on the direct product of AdS3, the squashed three-sphere and a four-torus (AdS3 \times SqS3 \times T4). We derive explicitly the Green-Schwarz action and discuss in detail the hidden integrable structure corresponding to local and non-local currents. We find that the model is classically integrable and that the currents generate a full psu(1, 1|2) superalgebra, even though the corresponding spacetime isometries are broken by the squashing