3,309 research outputs found
Cascade of Gregory-Laflamme Transitions and U(1) Breakdown in Super Yang-Mills
In this paper we consider black p-branes on square torus. We find an
indication of a cascade of Gregory-Laflamme transitions between black p-brane
and (p-1)-brane. Through AdS/CFT correspondence, these transitions are related
to the breakdown of the U(1) symmetry in super Yang-Mills on torus. We argue a
relationship between the cascade and recent Monte-Carlo data.Comment: 15 pages, 3 figures, LaTeX, v2: comments and references added, v3:
minor changes and a reference adde
Three-point function of semiclassical states at weak coupling
We give the derivation of the previously announced analytic expression for
the correlation function of three heavy non-BPS operators in N=4
super-Yang-Mills theory at weak coupling. The three operators belong to three
different su(2) sectors and are dual to three classical strings moving on the
sphere. Our computation is based on the reformulation of the problem in terms
of the Bethe Ansatz for periodic XXX spin-1/2 chains. In these terms the three
operators are described by long-wave-length excitations over the ferromagnetic
vacuum, for which the number of the overturned spins is a finite fraction of
the length of the chain, and the classical limit is known as the Sutherland
limit. Technically our main result is a factorized operator expression for the
scalar product of two Bethe states. The derivation is based on a fermionic
representation of Slavnov's determinant formula, and a subsequent bosonisation.Comment: 28 pages, 5 figures, cosmetic changes and more typos corrected in v
Reggeon exchange from gauge/gravity duality
We perform the analysis of quark-antiquark Reggeon exchange in meson-meson
scattering, in the framework of the gauge/gravity correspondence in a confining
background. On the gauge theory side, Reggeon exchange is described as
quark-antiquark exchange in the t channel between fast projectiles. The
corresponding amplitude is represented in terms of Wilson loops running along
the trajectories of the constituent quarks and antiquarks. The paths of the
exchanged fermions are integrated over, while the "spectator" fermions are
dealt with in an eikonal approximation. On the gravity side, we follow a
previously proposed approach, and we evaluate the Wilson-loop expectation value
by making use of gauge/gravity duality for a generic confining gauge theory.
The amplitude is obtained in a saddle-point approximation through the
determination near the confining horizon of a Euclidean "minimal surface with
floating boundaries", i.e., by fixing the trajectories of the exchanged quark
and antiquark by means of a minimisation procedure, which involves both area
and length terms. After discussing, as a warm-up exercise, a simpler problem on
a plane involving a soap film with floating boundaries, we solve the
variational problem relevant to Reggeon exchange, in which the basic geometry
is that of a helicoid. A compact expression for the Reggeon-exchange amplitude,
including the effects of a small fermion mass, is then obtained through
analytic continuation from Euclidean to Minkowski space-time. We find in
particular a linear Regge trajectory, corresponding to a Regge-pole singularity
supplemented by a logarithmic cut induced by the non-zero quark mass. The
analytic continuation leads also to companion contributions, corresponding to
the convolution of the same Reggeon-exchange amplitude with multiple elastic
rescattering interactions between the colliding mesons.Comment: 60+1 pages, 14 figure
Wave functions and correlation functions for GKP strings from integrability
We develop a general method of computing the contribution of the vertex
operators to the semi-classical correlation functions of heavy string states,
based on the state-operator correspondence and the integrable structure of the
system. Our method requires only the knowledge of the local behavior of the
saddle point configuration around each vertex insertion point and can be
applied to cases where the precise forms of the vertex operators are not known.
As an important application, we compute the contributions of the vertex
operators to the three-point functions of the large spin limit of the
Gubser-Klebanov-Polyakov (GKP) strings in spacetime, left unevaluated
in our previous work [arXiv:1110.3949] which initiated such a study. Combining
with the finite part of the action already computed previously and with the
newly evaluated divergent part of the action, we obtain finite three-point
functions with the expected dependence of the target space boundary coordinates
on the dilatation charge and the spin.Comment: 80 pages, 7 figures, v2: typos and minor errors corrected, a
reference added, v3: typos and a reference corrected, published versio
Almost-Hermitian Random Matrices: Crossover from Wigner-Dyson to Ginibre eigenvalue statistics
By using the method of orthogonal polynomials we analyze the statistical
properties of complex eigenvalues of random matrices describing a crossover
from Hermitian matrices characterized by the Wigner- Dyson statistics of real
eigenvalues to strongly non-Hermitian ones whose complex eigenvalues were
studied by Ginibre.
Two-point statistical measures (as e.g. spectral form factor, number variance
and small distance behavior of the nearest neighbor distance distribution
) are studied in more detail. In particular, we found that the latter
function may exhibit unusual behavior for some parameter
values.Comment: 4 pages, RevTE
High Energy Bounds on Soft N=4 SYM Amplitudes from AdS/CFT
Using the AdS/CFT correspondence, we study the high-energy behavior of
colorless dipole elastic scattering amplitudes in N=4 SYM gauge theory through
the Wilson loop correlator formalism and Euclidean to Minkowskian analytic
continuation. The purely elastic behavior obtained at large impact-parameter L,
through duality from disconnected AdS_5 minimal surfaces beyond the
Gross-Ooguri transition point, is combined with unitarity and analyticity
constraints in the central region. In this way we obtain an absolute bound on
the high-energy behavior of the forward scattering amplitude due to the
graviton interaction between minimal surfaces in the bulk. The dominant
"Pomeron" intercept is bounded by alpha less than or equal to 11/7 using the
AdS/CFT constraint of a weak gravitational field in the bulk. Assuming the
elastic eikonal approximation in a larger impact-parameter range gives alpha
between 4/3 and 11/7. The actual intercept becomes 4/3 if one assumes the
elastic eikonal approximation within its maximally allowed range L larger than
exp{Y/3}, where Y is the total rapidity. Subleading AdS/CFT contributions at
large impact-parameter due to the other d=10 supergravity fields are obtained.
A divergence in the real part of the tachyonic KK scalar is cured by
analyticity but signals the need for a theoretical completion of the AdS/CFT
scheme.Comment: 25 pages, 3 eps figure
Phase diagram for non-axisymmetric plasma balls
Plasma balls and rings emerge as fluid holographic duals of black holes and
black rings in the hydrodynamic/gravity correspondence for the Scherk-Schwarz
AdS system. Recently, plasma balls spinning above a critical rotation were
found to be unstable against m-lobed perturbations. In the phase diagram of
stationary solutions the threshold of the instability signals a bifurcation to
a new phase of non-axisymmetric configurations. We find explicitly this family
of solutions and represent them in the phase diagram. We discuss the
implications of our results for the gravitational system. Rotating
non-axisymmetric black holes necessarily radiate gravitational waves. We thus
emphasize that it would be important, albeit possibly out of present reach, to
have a better understanding of the hydrodynamic description of gravitational
waves and of the gravitational interaction between two bodies. We also argue
that it might well be that a non-axisymmetric m-lobed instability is also
present in Myers-Perry black holes for rotations below the recently found
ultraspinning instability.Comment: 1+22 pages, 3 figures. v2: minor corrections and improvements,
matches published versio
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
Hydrodynamics from charged black branes
We extend the recent work on fluid-gravity correspondence to charged
black-branes by determining the metric duals to arbitrary charged fluid
configuration up to second order in the boundary derivative expansion. We also
derive the energy-momentum tensor and the charge current for these
configurations up to second order in the boundary derivative expansion. We find
a new term in the charge current when there is a bulk Chern-Simons interaction
thus resolving an earlier discrepancy between thermodynamics of charged
rotating black holes and boundary hydrodynamics. We have also confirmed that
all our expressions are covariant under boundary Weyl-transformations as
expected.Comment: 0+ 31 Pages; v2: 0+33 pages, typos corrected and new sections (in
appendix) added; v3:published versio
Exact fuzzy sphere thermodynamics in matrix quantum mechanics
We study thermodynamical properties of a fuzzy sphere in matrix quantum
mechanics of the BFSS type including the Chern-Simons term. Various quantities
are calculated to all orders in perturbation theory exploiting the one-loop
saturation of the effective action in the large-N limit. The fuzzy sphere
becomes unstable at sufficiently strong coupling, and the critical point is
obtained explicitly as a function of the temperature. The whole phase diagram
is investigated by Monte Carlo simulation. Above the critical point, we obtain
perfect agreement with the all order results. In the region below the critical
point, which is not accessible by perturbation theory, we observe the Hagedorn
transition. In the high temperature limit our model is equivalent to a totally
reduced model, and the relationship to previously known results is clarified.Comment: 22 pages, 14 figures, (v2) some typos correcte
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