328 research outputs found
Fat Magnon
We consider a D-brane type state which shares the characteristic of the
recently found giant magnon of Hofman and Maldacena. More specifically we find
a bound state of giant graviton (D3-brane) and giant magnon (F-string), which
has exactly the same anomalous dimension as that of the giant magnon. It is
described by the D3-brane with electric flux which is topologically a
elongated by the electric flux. The angular momentum and energy are infinite,
but split sensibly into two parts -- the infinite part precisely the same as
that of the giant magnon and the finite part which can be identified as the
contribution from the giant graviton. We discuss that the corresponding dual
gauge theory operator is not a simple chain type but rather admixture of the
(sub-)determinant and chain types.Comment: 18 pages, 5 figures; v2 references added; v3 a reference added; v4
added a reference and discussions on the physical CFT operator. The version
to appear in JHE
Models with Quartic Potential of Dynamical SUSY Breaking in Meta-Stable Vacua
We search for models of dynamical SUSY breaking in meta-stable vacua which
might have dual string descriptions with a few brane probes. Two models with
quartic superpotential are proposed: One of them might be closely related to
the dual gauge theory to the flavored Maldacena-Nunez geometry by Casero,
Nunez, and Paredes with a few additional brane probes corresponding to massive
flavors. The other model might be dual to the Klebanov-Strassler geometry with
one fractional D3-brane and a few D7-branes as probes.Comment: 16 pages; v2 added the reference hep-th/0608063 which is the first to
have added a quartic potential stabilizing the would-be problematic modulu
Airy Function and 4d Quantum Gravity
We study four-dimensional quantum gravity with negative cosmological constant
in the minisuperspace approximation and compute the partition function for the
boundary geometry. In this approximation scheme the path integrals become
dominated by a class of asymptotically AdS "microstate geometries." Despite the
fact that the theory is pure Einstein gravity without supersymmetry, the result
precisely reproduces, up to higher curvature corrections, the Airy function in
the partition function of the maximally supersymmetric
Chern-Simons-matter (CSM) theory which sums up all perturbative
corrections. We also show that this can be interpreted as a concrete
realization of the idea that the CFT partition function is a solution to the
Wheeler-DeWitt equation as advocated in the holographic renormalization group.
Furthermore, the agreement persists upon the inclusion of a string probe and it
reproduces the Airy function in the vev of half-BPS Wilson loops in the CSM
theory. These results may suggest that the supergravity path integrals localize
to the minisuperspace in certain cases and the use of the minisuperspace
approximation in AdS/CFT may be a viable approach to study corrections to
large CFTs.Comment: 17 page
Branes Ending On Branes In A Tachyon Model
In a tachyon model proposed by Minahan and Zwiebach and derived in the
boundary string field theory, we construct various new solutions which
correspond to nontrivial brane configurations in string theory. Our solutions
include Dp-D(p-2) bound states, (F, Dp) bound states, string junctions,
D(p-2)-branes ending on a Dp-brane, D(p-2)-branes suspended between parallel
Dp-branes and their non-commutative generalizations. We find the Bogomol'nyi
bounds and the BPS equations for some of our solutions, and check the physical
consistency of our solutions with the D-brane picture by looking at the
distributions of their energies and RR-charges in space. We also give
conjectures for a few other brane configurations.Comment: 19 pages, LaTeX, minor corrections and references adde
Topological Matrix Model
Starting from the primal principle based on the noncommutative nature of
(9+1)-dimensional spacetime, we construct a topologically twisted version of
the supersymmetric reduced model with a certain modification. Our formulation
automatically provides extra 1+1 dimensions, thereby the dimensions of
spacetime are promoted to 10+2. With a suitable gauge choice, we can reduce the
model with (10+2)-dimensional spacetime to the one with (9+1)-dimensions and
thus we regard this gauge as the light-cone gauge. It is suggested that the
model so obtained would describe the light-cone F-theory. From this viewpoint
we argue the relation of the reduced model to the matrix model of M-theory and
the SL(2,Z) symmetry of type IIB string theory. We also discuss the general
covariance of the matrix model in a broken phase, and make some comments on the
background independence.Comment: 18 pages, LaTeX, no figures, minor corrections and modifications,
references adde
Anomalous radius shift in AdS(4)/CFT(3)
We study higher order corrections to the radius/M2-brane charge of AdS_4 x
S^7/Z_k. There are two sources of corrections: one from the orbifold
singularity of C^4/Z_k, and the other from the discrete torsion associated with
the homology 3-cycle H_3(S^7/Z_k,Z) = Z_k. We give a precise formula for the
charge shift. These corrections are relevant, for example, at two loops in the
AdS_4 x CP^3 sigma model, and therefore for the strong coupling test of the all
loop Bethe ansatz.Comment: 16 pages; v2: The Type IIA D-brane probe calculation has been
corrected, and now agrees with the M theory calculation. Appendix on
conventions for RR fields and D-brane actions added. Note added on a possible
correction due to a parity anomaly. References adde
Three dimensional Janus and time-dependent black holes
We show that the three dimensional Janus geometry can be embedded into the
type IIB supergravity and discuss its dual CFT description. We also find exact
solutions of time dependent black holes with a nontrivial dilaton field in
three and higher dimensions as an application of the Janus construction.Comment: 17 pages, 1 figure; v2 minor corrections, references adde
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