197 research outputs found
The Plasma Puddle as a Perturbative Black Hole
We argue that the weak coupling regime of a large N gauge theory in the Higgs
phase contains black hole-like objects. These so-called ``plasma puddles'' are
meta-stable lumps of hot plasma lying in locally un-Higgsed regions of space.
They decay via O(1/N) thermal radiation and, perhaps surprisingly, absorb all
incident matter. We show that an incident particle of energy E striking the
plasma puddle will shower into an enormous number of decay products whose
multiplicity grows linearly with E, and whose average energy is independent of
E. Once these ultra-soft particles reach the interior they are thermalized by
the plasma within, and so the object appears ``black.'' We determine some gross
properties like the size and temperature of the the plasma puddle in terms of
fundamental parameters in the gauge theory. Interestingly, demanding that the
plasma puddle emit thermal Hawking radiation implies that the object is black
(i.e. absorbs all incident particles), which implies classical stability, which
implies satisfaction of the Bekenstein entropy bound. Because of the AdS/CFT
duality and the many similarities between plasma puddles and black holes, we
conjecture that black objects are a robust feature of quantum gravity.Comment: 23 pages, 3 figures, V2: minor changes, ref added, appendix A.5 moved
to body of pape
The Three Dimensional Dual of 4D Chirality
Chiral gauge theories can be defined in four-dimensional Anti de Sitter
space, but AdS boundary conditions explicitly break the chiral symmetry in a
specific, well defined manner, which in turns results in an anomalous Ward
identity. When the 4D theory admits a dual description in terms of a 3D CFT,
the 3D dual of the broken chiral symmetry is a certain double-trace deformation
of the CFT, which produces the same anomalous chiral Ward identities that
obtains in the 4D bulk theory.Comment: 10 pages, small misprints corrected, reference [16] updated. Version
to appear in JHE
A silence black hole: Hawking radiation at the Hagedorn temperature
We compute semi-classically the Hawking emission for different types of black
hole in type II string theory. In particular we analyze the thermal transition
between NS5 branes and Little String Theory, finding compelling evidence for
information recovering. We find that once the near horizon limit is taken the
emission of a full family of models is exactly thermal even if back-reaction is
taken into account. Consequently these theories are non-unitary and can not
convey any information about the black hole internal states. It is argue that
this behaviour matches the string theory expectations. We suggest a plausible
reason for the vanishing of the jet-quenching parameter in such theories.Comment: 18 pages, harvma
Phase structure of matrix quantum mechanics at finite temperature
We study matrix quantum mechanics at finite temperature by Monte Carlo
simulation. The model is obtained by dimensionally reducing 10d U(N) pure
Yang-Mills theory to 1d. Following Aharony et al., one can view the same model
as describing the high temperature regime of (1+1)d U(N) super Yang-Mills
theory on a circle. In this interpretation an analog of the deconfinement
transition was conjectured to be a continuation of the black-hole/black-string
transition in the dual gravity theory. Our detailed analysis in the critical
regime up to N=32 suggests the existence of the non-uniform phase, in which the
eigenvalue distribution of the holonomy matrix is non-uniform but gapless. The
transition to the gapped phase is of second order. The internal energy is
constant (giving the ground state energy) in the uniform phase, and rises
quadratically in the non-uniform phase, which implies that the transition
between these two phases is of third order.Comment: 17 pages, 9 figures, (v2) refined arguments in section 3 ; reference
adde
Anti-de Sitter boundary in Poincare coordinates
We study the space-time boundary of a Poincare patch of Anti-de Sitter (AdS)
space. We map the Poincare AdS boundary to the global coordinate chart and show
why this boundary is not equivalent to the global AdS boundary. The Poincare
AdS boundary is shown to contain points of the bulk of the entire AdS space.
The Euclidean AdS space is also discussed. In this case one can define a
semi-global chart that divides the AdS space in the same way as the
corresponding Euclidean Poincare chart.Comment: In this revised version we add a discussion of the physical
consequences of the choice of a coordinate system for AdS space. We changed
figure 1 and added more references. Version to be published in Gen. Relat.
Grav
On RG-flow and the Cosmological Constant
The AdS/CFT correspondence implies that the effective action of certain
strongly coupled large gauge theories satisfy the Hamilton-Jacobi equation
of 5d gravity. Using an analogy with the relativistic point particle, I
construct a low energy effective action that includes the Einstein action and
obeys a Callan-Symanzik-type RG-flow equation. It follows from the flow
equation that under quite general conditions the Einstein equations admit a
flat space-time solution, but other solutions with non-zero cosmological
constant are also allowed. I discuss the geometric interpretation of this
result in the context of warped compactifications.Comment: 11 pages, 1 figure, contribution to the proceedings of Strings '99,
misprint correcte
Wilson Loops in Large N Theories
Talk presented at Strings '99 in Potsdam, Germany (July 19 - 24, 1999).Comment: 11 pages; submitted to Proceedings of Strings '9
A Dilatonic Deformation of AdS_5 and its Field Theory Dual
We find a nonsupersymmetric dilatonic deformation of geometry as an
exact nonsingular solution of the type IIB supergravity. The dual gauge theory
has a different Yang-Mills coupling in each of the two halves of the boundary
spacetime divided by a codimension one defect. We discuss the geometry of our
solution in detail, emphasizing the structure of the boundary, and also study
the string configurations corresponding to Wilson loops. We also show that that
the background is stable under small scalar perturbations.Comment: 19 pages, 8 figures, v2 minor changes, added references, version to
appear in JHE
Holography from Conformal Field Theory
The locality of bulk physics at distances below the AdS length is one of the
remarkable aspects of AdS/CFT duality, and one of the least tested. It requires
that the AdS radius be large compared to the Planck length and the string
length. In the CFT this implies a large-N expansion and a gap in the spectum of
anomalous dimensions. We conjecture that the implication also runs in the other
direction, so that any CFT with a planar expansion and a large gap has a local
bulk dual. For an abstract CFT we formulate the consistency conditions, most
notably crossing symmetry, and show that the conjecture is true in a broad
range of CFT's, to first nontrivial order in 1/N^2: any CFT with a gap and a
planar expansion is generated via the AdS/CFT dictionary from a local bulk
interaction. We establish this result by a counting argument on each side, and
also investigate various properties of some explicit solutions.Comment: 49 pages. Minor corrections. Figure and references adde
The Moduli Space and M(atrix) Theory of 9d N=1 Backgrounds of M/String Theory
We discuss the moduli space of nine dimensional N=1 supersymmetric
compactifications of M theory / string theory with reduced rank (rank 10 or
rank 2), exhibiting how all the different theories (including M theory
compactified on a Klein bottle and on a Mobius strip, the Dabholkar-Park
background, CHL strings and asymmetric orbifolds of type II strings on a
circle) fit together, and what are the weakly coupled descriptions in different
regions of the moduli space. We argue that there are two disconnected
components in the moduli space of theories with rank 2. We analyze in detail
the limits of the M theory compactifications on a Klein bottle and on a Mobius
strip which naively give type IIA string theory with an uncharged orientifold
8-plane carrying discrete RR flux. In order to consistently describe these
limits we conjecture that this orientifold non-perturbatively splits into a
D8-brane and an orientifold plane of charge (-1) which sits at infinite
coupling. We construct the M(atrix) theory for M theory on a Klein bottle (and
the theories related to it), which is given by a 2+1 dimensional gauge theory
with a varying gauge coupling compactified on a cylinder with specific boundary
conditions. We also clarify the construction of the M(atrix) theory for
backgrounds of rank 18, including the heterotic string on a circle.Comment: 43 pages, 7 figures, JHEP format. v3: typos correcte
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