37 research outputs found
S-matrix for magnons in the D1-D5 system
We show that integrability and symmetries of the near horizon geometry of the
D1-D5 system determine the S-matrix for the scattering of magnons with
polarizations in AdS3 S3 completely up to a phase. Using
semi-classical methods we evaluate the phase to the leading and to the one-loop
approximation in the strong coupling expansion. We then show that the phase
obeys the unitarity constraint implied by the crossing relations to the
one-loop order. We also verify that the dispersion relation obeyed by these
magnons is one-loop exact at strong coupling which is consistent with their BPS
nature.Comment: 40 pages, Latex, Role of Virasoro constraints clarified, version
matches with published versio
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
Intertwining Relations for the Deformed D1D5 CFT
The Higgs branch of the D1D5 system flows in the infrared to a
two-dimensional N=(4,4) SCFT. This system is believed to have an "orbifold
point" in its moduli space where the SCFT is a free sigma model with target
space the symmetric product of copies of four-tori; however, at the orbifold
point gravity is strongly coupled and to reach the supergravity point one needs
to turn on the four exactly marginal deformations corresponding to the blow-up
modes of the orbifold SCFT. Recently, technology has been developed for
studying these deformations and perturbing the D1D5 CFT off its orbifold point.
We present a new method for computing the general effect of a single
application of the deformation operators. The method takes the form of
intertwining relations that map operators in the untwisted sector before
application of the deformation operator to operators in the 2-twisted sector
after the application of the deformation operator. This method is
computationally more direct, and may be of theoretical interest. This line of
inquiry should ultimately have relevance for black hole physics.Comment: latex, 23 pages, 3 figure
A Spin Chain for the Symmetric Product CFT_2
We consider "gauge invariant" operators in Sym^N T^4, the symmetric product
orbifold of N copies of the 2d supersymmetric sigma model with T^4 target. We
discuss a spin chain representation for single-cycle operators and study their
two point functions at large N. We perform systematic calculations at the
orbifold point ("tree level"), where non-trivial mixing is already present, and
some sample calculations to first order in the blow-up mode of the orbifold
("one loop").Comment: 52 pages, 10 figure
Emission from the D1D5 CFT: Higher Twists
We study a certain class of nonextremal D1D5 geometries and their ergoregion
emission. Using a detailed CFT computation and the formalism developed in
arXiv:0906.2015 [hep-th], we compute the full spectrum and rate of emission
from the geometries and find exact agreement with the gravity answer.
Previously, only part of the spectrum had been reproduced using a CFT
description. We close with a discussion of the context and significance of the
calculation.Comment: 39 pages, 6 figures, late
PP-wave String Interactions from String Bit Model
We construct the string states ,
and in the Hilbert space of the quantum
mechanical orbifold model so as to calculate the three point functions and the
matrix elements of the light-cone Hamiltonian from the interacting string bit
model. With these string states we show that the three point functions and the
matrix elements of the Hamiltonian derived from the interacting string bit
model up to order precisely match with those computed from the
perturbative SYM theory in BMN limit.Comment: 20 pages, no figure, LaTeX, some changes made and references adde
Excitations in the deformed D1D5 CFT
We perform some simple computations for the first order deformation of the
D1D5 CFT off its orbifold point. It had been shown earlier that under this
deformation the vacuum state changes to a squeezed state (with the further
action of a supercharge). We now start with states containing one or two
initial quanta and write down the corresponding states obtained under the
action of deformation operator. The result is relevant to the evolution of an
initial excitation in the CFT dual to the near extremal D1D5 black hole: when a
left and a right moving excitation collide in the CFT, the deformation operator
spreads their energy over a larger number of quanta, thus evolving the state
towards the infrared.Comment: 26 pages, Latex, 4 figure
Deforming the D1D5 CFT away from the orbifold point
The D1D5 brane bound state is believed to have an `orbifold point' in its
moduli space which is the analogue of the free Yang Mills theory for the D3
brane bound state. The supergravity geometry generated by D1 and D5 branes is
described by a different point in moduli space, and in moving towards this
point we have to deform the CFT by a marginal operator: the `twist' which links
together two copies of the CFT. In this paper we find the effect of this
deformation operator on the simplest physical state of the CFT -- the Ramond
vacuum. The twist deformation leads to a final state that is populated by pairs
of excitations like those in a squeezed state. We find the coefficients
characterizing the distribution of these particle pairs (for both bosons and
fermions) and thus write this final state in closed form.Comment: 30 pages, 4 figures, Late
p-wave Holographic Superconductors and five-dimensional gauged Supergravity
We explore five-dimensional and
SO(6) gauged supergravities as frameworks for condensed matter applications.
These theories contain charged (dilatonic) black holes and 2-forms which have
non-trivial quantum numbers with respect to U(1) subgroups of SO(6). A question
of interest is whether they also contain black holes with two-form hair with
the required asymptotic to give rise to holographic superconductivity. We first
consider the case, which contains a complex two-form potential
which has U(1) charge . We find that a slight
generalization, where the two-form potential has an arbitrary charge , leads
to a five-dimensional model that exhibits second-order superconducting
transitions of p-wave type where the role of order parameter is played by
, provided . We identify the operator that condenses
in the dual CFT, which is closely related to Super Yang-Mills
theory with chemical potentials. Similar phase transitions between R-charged
black holes and black holes with 2-form hair are found in a generalized version
of the gauged supergravity Lagrangian where the two-forms have
charge .Comment: 35 pages, 14 figure
Odderon in baryon-baryon scattering from the AdS/CFT correspondence
Based on the AdS/CFT correspondence, we present a holographic description of
various C-odd exchanges in high energy baryon-baryon and baryon-antibaryon
scattering, and calculate their respective contributions to the difference in
the total cross sections. We predict that, due to the warp factor of AdS_5, the
total cross section in pp collisions is larger than in p\bar{p} collisions at
asymptotically high energies.Comment: 23 pages, v2: minor changes, to be published in JHE