143 research outputs found
Propagators for massive symmetric tensor and p-forms in AdS(d+1)
We construct propagators in Euclidean AdS(d+1) space-time for massive p-forms
and massive symmetric tensors.Comment: 22 page
Rolling Tachyons and Decaying Branes
We present new rolling tachyon solutions describing the classical decay of
D-branes. Our methods are simpler than those appearing in recent works, yet our
results are exact in classical string theory. The role of pressure in the decay
is studied using tachyon profiles with spatial variation. In this case the
final state involves an array of codimension one D-branes rather than static,
pressureless tachyon matter.Comment: 24 page
Marginal Deformations from Branes
We study brane configurations for four dimensional N=1 supersymmetric gauge
theories with quartic superpotentials which flow in the infrared to manifolds
of interacting superconformal fixed points. We enumerate finite N=2 theories,
from which a large class of marginal N=1 theories descend. We give the brane
descriptions of these theories in Type IIA and Type IIB string theory. The Type
IIB descriptions are in terms of D3 branes in orientifold and generalized
conifold backgrounds. We calculate the Weyl and Euler anomalies in these
theories, and find that they are equal in elliptic models and unequal in a
large class of finite N=2 and marginal N=1 non-elliptic theories.Comment: 42 pages, minor changes, references adde
Some Aspects of the AdS/CFT Correspondence
This is a very brief review of some aspects of the AdS/CFT correspondence
with an emphasis on the role of the topology of the boundary and the meaning of
the sum over bulk geometries. To appear in the proceedings of the 73rd Meeting
between Physicists and Mathematicians ``(A)dS/CFT correspondence,'' Strasbourg,
September 11-13, 2003.Comment: LaTeX, 32 pages, 1 figure. To appear in the proceedings of the 73rd
Meeting between Physicists and Mathematicians ``(A)dS/CFT correspondence,''
Strasbourg, September 11-13, 2003. v3: minor changes and references adde
Instabilities of the Small Black Hole: a view from N=4 SYM
We compute a one-loop effective action for the constant modes of the scalars
and the Polyakov loop matrix of N=4 SYM on S^3 at finite temperature and weak
't Hooft coupling. Above a critical temperature, the effective potential
develops new unstable directions accompanied by new saddle points which only
preserve an SO(5) subgroup of the SO(6) global R-symmetry. We identify this
phenomenon as the weak coupling version of the well known Gregory-Laflamme
localization instability in the gravity dual of the strongly coupled field
theory: The small AdS_5 black hole when viewed as a ten dimensional,
asymptotically AdS_5 X S^5 solution smeared on the S^5 is unstable to
localization on S^5. Our effective potential, in a specific Lorentzian
continuation, can provide a qualitative holographic description of the decay of
the "topological black hole'' into the AdS bubble of nothing.Comment: 39 pages, 6 figures, uses JHEP3.cls, references adde
On Marginal Deformations in Superstring Field Theory
We use level truncated superstring field theory to obtain the effective
potential for the Wilson line marginal deformation parameter which corresponds
to the constant vacuum expectation value of the U(1) gauge field on the D-brane
in a particular direction. We present results for both the BPS and the non-BPS
D-brane. In the case of non-BPS D-brane the effective potential has branches
corresponding to the extrema of the tachyon potential. In the branch with
vanishing tachyon vev (M-branch), the effective potential becomes flatter as
the level of the approximation is increased. The branch which corresponds to
the stable vacuum after the tachyon has condensed (V-branch) exists only for a
finite range of values of marginal deformation parameter. We use our results to
find the mass of the gauge field in the stable tachyonic vacuum. We find this
mass to be of a non-zero value which seems to stabilize as the level
approximation is improved.Comment: 20 pages, 8 figure
A Non-Supersymmetric Large-N 3D CFT And Its Gravity Dual
We propose a three dimensional non-supersymmetric theory that is conformal in
the large N limit. In a certain well defined bosonic sub-sector of gauge
invariant operators, this theory is planar equivalent to the theory recently
proposed by Aharony, Bergman, Jafferis and Maldacena as the theory on multiple
M2 branes at an orbifold singularity. We discuss the realization of the theory
on a brane configuration of type 0B string theory. Moreover, we propose an 11D
gravity dual, obtained by a projection of M-theory on AdS4 x S7 / Z_k.Comment: 11 pages, LaTex. 2 eps figures. v2: minor changes, references added.
v3: version to appear in JHE
N=4 SYM on S^3 with Near Critical Chemical Potentials
We study the N = 4 theory at weak coupling, on a three sphere in the grand
canonical ensemble with R symmetry chemical potentials. We focus attention on
near critical values for the chemical potentials, above which the classical
theory has no ground state. By computing a one loop effective potential for the
light degrees of freedom in this regime, we show the existence of flat
directions of complex dimension N, 2N and 3N for one, two and three critical
chemical potentials respectively; these correspond to one half, one quarter and
one-eighth BPS states becoming light respectively at the critical values. At
small finite temperature we show that the chemical potentials can be continued
beyond their classical limiting values to yield a deconfined metastable phase
with lifetime diverging in the large N limit. Our low temperaure analysis
complements the high temperature metastability found by Yamada and Yaffe. The
resulting phase diagram at weak coupling bears a striking resemblance to the
strong coupling phase diagram for charged AdS black holes. Our analysis also
reveals subtle qualitative differences between the two regimes.Comment: 34 pages, 4 figure
The propagator for a general form field in
Using the known propagator equations for 0,1 and 2 forms in AdS_{d+1}, we
find the p-form field propagator equations in dimensions where the forms are
Poincare dual. Since the general equation obeyed by the propagators is linear
in dimension, this gives us the equation obeyed by the propagators for any d.
Furthermore, based on the Poincare duality formulas for 0,1,2 and 3 forms we
conjecture the general form of the Poincare duality formulas, and check them
against the previously found propagator equations. The whole structure is
self-consistent. Once we have the equations, we can easily obtain all the
p-form field propagators in AdS_{d+1}. The generalization to massive p-forms
can also be easily done.Comment: Extra chapter added on massive p-forms. 10 pages, REVTE
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