240 research outputs found
On the Phase Transition of Conformal Field Theories with Holographic Duals
We study the thermodynamic relations of conformal field theories (CFTs),
which are holographically dual to anti-de Sitter-Schwarzschild bulk
space-times. A Cardy-Verlinde formula is derived thermodynamically for CFTs
living on S^n x R with S^n having an arbitrary radius. The Hawking-Page phase
transition of the CFT is described using Landau's theory of phase transitions,
and an alternative derivation of the Cardy-Verlinde formula is presented. The
condensate in the high temperature phase is identified as being composed of
radiational matter.Comment: 10 pages, final version to appear on PL
AdS_3/CFT_2 correspondence at finite temperature
The AdS/CFT correspondence is established for the AdS_3 space compactified on
a solid torus with the CFT field on the boundary. Correlation functions that
correspond to the bulk theory at finite temperature are obtained in the
regularization a'la Gubser, Klebanov, and Polyakov. The BTZ black hole
solutions in AdS_3 are T-dual to the solution in the AdS_3 space without
singularity.Comment: 9pp., LaTe
Radiative distortion of kinematic edges in cascade decays
Kinematic edges of cascade decays of new particles produced in high-energy collisions may provide important constraints on the involved particles' masses. For the exemplary case of gluino decay gËâqqÂŻÏË into a pair of quarks and a neutralino through a squark resonance, we study the hadronic invariant mass distribution in the vicinity of the kinematic edge. We perform a next-to-leading order calculation in the strong coupling αs and the ratio of squark width and squark mass ÎqË/mqË, based on a systematic expansion in ÎqË/mqË. The separation into hard, collinear and soft contributions elucidates the process-dependent and universal features of distributions in the edge region, represented by on-shell decay matrix elements, universal jet functions and a soft function that depends on the resonance propagator and soft Wilson lines.The work of M.B. has been supported in part by the Bundesministerium fĂŒr Bildung und Forschung (BMBF) under project no. 05H15W0CAA. L.J. was partially supported by the DFG contract STU 615/1-1, and M.U. is partially supported by the STFC grant ST/L000385/1 and her research is funded by a Royal Society Dorothy Hodgkin Research Fellowship
Running Scaling Dimensions in Holographic Renormalization Group Flows
Holographic renormalization group flows can be interpreted in terms of
effective field theory. Based on such an interpretation, a formula for the
running scaling dimensions of gauge-invariant operators along such flows is
proposed. The formula is checked for some simple examples from the AdS/CFT
correspondence, but can be applied also in non-AdS/non-CFT cases.Comment: 14 pages, 2 figure
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
Effective AdS/renormalized CFT
For an effective AdS theory, we present a simple prescription to compute the
renormalization of its dual boundary field theory. In particular, we define
anomalous dimension holographically as the dependence of the wave-function
renormalization factor on the radial cutoff in the Poincare patch of AdS. With
this definition, the anomalous dimensions of both single- and double- trace
operators are calculated. Three different dualities are considered with the
field theory being CFT, CFT with a double-trace deformation and spontaneously
broken CFT. For the second dual pair, we compute scaling corrections at the UV
and IR fixed points of the RG flow triggered by the double-trace deformation.
For the last case, we discuss whether our prescription is sensitive to the AdS
interior or equivalently, the IR physics of the dual field theory.Comment: 20 pages, 3 figure
Multitrace deformations, Gamow states, and Stability of AdS/CFT
We analyze the effect of multitrace deformations in conformal field theories
at leading order in a large N approximation. These theories admit a description
in terms of a weakly coupled gravity dual. We show how the deformations can be
mapped into boundary terms of the gravity theory and how to reproduce the RG
equations found in field theory. In the case of doubletrace deformations, and
for bulk scalars with masses in the range , the deformed
theory flows between two fixed points of the renormalization group, manifesting
a resonant behavior at the scale characterizing the transition between the two
CFT's. On the gravity side the resonance is mapped into an IR non-normalizable
mode (Gamow state) whose overlap with the UV region increases as the dual
operator approaches the free field limit. We argue that this resonant behavior
is a generic property of large N theories in the conformal window, and
associate it to a remnant of the Nambu-Goldstone mode of dilatation invariance.
We emphasize the role of nonminimal couplings to gravity and establish a
stability theorem for scalar/gravity systems with AdS boundary conditions in
the presence of arbitrary boundary potentials and nonminimal coupling.Comment: 14 pages, references added, introduction change
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