7,805 research outputs found
A Holographic Prediction of the Deconfinement Temperature
We argue that deconfinement in AdS/QCD models occurs via a first order
Hawking-Page type phase transition between a low temperature thermal AdS space
and a high temperature black hole. Such a result is consistent with the
expected temperature independence, to leading order in 1/N_c, of the meson
spectrum and spatial Wilson loops below the deconfinement temperature. As a
byproduct, we obtain model dependent deconfinement temperatures T_c in the hard
and soft wall models of AdS/QCD. Our result for T_c in the soft wall model is
close to a recent lattice prediction.Comment: 4 pages, 1 figure; v2 ref added, minor changes; v3 refs added,
discussion modified, to appear in PR
Charged Black Hole in a Canonical Ensemble
We consider the thermodynamics of a charged black hole enclosed in a cavity.
The charge in the cavity and the temperature at the walls are fixed so that we
have a canonical ensemble. We derive the phase structure and stability of black
hole equilibrium states. We compare our results to that of other work which
uses asymptotically anti-de Sitter boundary conditions to define the
thermodynamics. The thermodynamic properties have extensive similarities which
suggest that the idea of AdS holography is more dependent on the existence of
the boundary than on the exact details of asymptotically AdS metrics.Comment: 9 pages; 4 multipart figure
BPS surface observables in six-dimensional (2,0) theory
The supergroup OSp(8*|4), which is the superconformal group of (2,0) theory
in six dimensions, is broken to the subgroup OSp(4|2)xOSp(4|2) by demanding the
invariance of a certain product in a superspace with eight bosonic and four
fermionic dimensions. We show that this is consistent with the symmetry
breaking induced by the presence of a flat two-dimensional BPS surface in the
usual (2,0) superspace, which has six bosonic and sixteen fermionic dimensions.Comment: 9 pages, LaTeX. v2: reference adde
Thermodynamics and Stability of Higher Dimensional Rotating (Kerr) AdS Black Holes
We study the thermodynamic and gravitational stability of Kerr anti-de Sitter
black holes in five and higher dimensions. We show, in the case of equal
rotation parameters, , that the Kerr-AdS background metrics become
stable, both thermodynamically and gravitationally, when the rotation
parameters take values comparable to the AdS curvature radius. In turn, a
Kerr-AdS black hole can be in thermal equilibrium with the thermal radiation
around it only when the rotation parameters become not significantly smaller
than the AdS curvature radius. We also find with equal rotation parameters that
a Kerr-AdS black hole is thermodynamically favored against the existence of a
thermal AdS space, while the opposite behavior is observed in the case of a
single non-zero rotation parameter. The five dimensional case is however
different and also special in that there is no high temperature thermal AdS
phase regardless of the choice of rotation parameters. We also verify that at
fixed entropy, the temperature of a rotating black hole is always bounded above
by that of a non-rotating black hole, in four and five dimensions, but not in
six and more dimensions (especially, when the entropy approaches zero or the
minimum of entropy does not correspond to the minimum of temperature). In this
last context, the six dimensional case is marginal.Comment: 15 pages, 23 eps figures, RevTex
AdS/CFT, Multitrace Deformations and New Instabilities of Nonlocal String Theories
We study "multitrace" deformations of large N master fields in models with a
mass gap. In particular, we determine the conditions for the multitrace
couplings to drive tachyonic instabilities. These tachyons represent new local
instabilities of the associated nonlocal string theories. In the particular
case of Dp-branes at finite temperature, we consider topology-changing phase
transitions and the effect of multitrace perturbations on the corresponding
phase diagrams.Comment: harvmac. 28 pages. 9 eps figure
Vortex Counting and Lagrangian 3-manifolds
To every 3-manifold M one can associate a two-dimensional N=(2,2)
supersymmetric field theory by compactifying five-dimensional N=2
super-Yang-Mills theory on M. This system naturally appears in the study of
half-BPS surface operators in four-dimensional N=2 gauge theories on one hand,
and in the geometric approach to knot homologies, on the other. We study the
relation between vortex counting in such two-dimensional N=(2,2) supersymmetric
field theories and the refined BPS invariants of the dual geometries. In
certain cases, this counting can be also mapped to the computation of
degenerate conformal blocks in two-dimensional CFT's. Degenerate limits of
vertex operators in CFT receive a simple interpretation via geometric
transitions in BPS counting.Comment: 70 pages, 29 figure
Local Differential Geometry as a Representation of the SUSY Oscillator
This work proposes a natural extension of the Bargmann-Fock representation to
a SUSY system. The main objective is to show that all essential structures of
the n-dimensional SUSY oscillator are supplied by basic differential
geometrical notions on an analytical R^n, except for the scalar product which
is the only additional ingredient. The restriction to real numbers implies only
a minor loss of structure but makes the essential features clearer. In
particular, euclidean evolution is enforced naturally by identification with
the 1-parametric group of dilations.Comment: 10 pages, late
A Note on Charged Black Holes in AdS space and the Dual Gauge Theories
We study the thermodynamics and the phase structures of Reissner-Nordstrom
and Born-Infeld black holes in AdS space by constructing ``off-shell'' free
energies using thermodynamic quantities derived directly from the action. We
then use these results to propose ``off-shell'' effective potentials for the
respective boundary gauge theories. The saddle points of the potentials
describe all the equilibrium phases of the gauge theories.Comment: LaTeX, 21+1 pages, 7 figure
Shining a Gluon Beam Through Quark-Gluon Plasma
We compute the energy density radiated by a quark undergoing circular motion
in strongly coupled supersymmetric Yang-Mills plasma. If it
were in vacuum, this quark would radiate a beam of strongly coupled radiation
whose angular distribution has been characterized and is very similar to that
of synchrotron radiation produced by an electron in circular motion in
electrodynamics. Here, we watch this beam of gluons getting quenched by the
strongly coupled plasma. We find that a beam of gluons of momenta is attenuated rapidly, over a distance in
a plasma with temperature . As the beam propagates through the plasma at the
speed of light, it sheds trailing sound waves with momenta .
Presumably these sound waves would thermalize in the plasma if they were not
hit soon after their production by the next pulse of gluons from the
lighthouse-like rotating quark. At larger and larger , the trailing sound
wave becomes less and less prominent. The outward going beam of gluon radiation
itself shows no tendency to spread in angle or to shift toward larger
wavelengths, even as it is completely attenuated. In this regard, the behavior
of the beam of gluons that we analyze is reminiscent of the behavior of jets
produced in heavy ion collisions at the LHC that lose a significant fraction of
their energy without appreciable change in their angular distribution or their
momentum distribution as they plow through the strongly coupled quark-gluon
plasma produced in these collisions.Comment: 16 pages, 4 figure
A Note on Chiral Symmetry Breaking from Intersecting Branes
In this paper, we will consider the chiral symmetry breaking in the
holographic model constructed from the intersecting brane configuration, and
investigate the Nambu-Goldstone bosons associated with this symmetry breaking.Comment: 16 pp, minor changes, to appear PR
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