122 research outputs found
Non-supersymmetric Conifold
We find a new family of non-supersymmetric numerical solutions of IIB
supergravity which are dual to the N=1 cascading "conifold" theory perturbed by
certain combinations of relevant single trace and marginal double trace
operators with non infinitesimal couplings. The SUSY is broken but the
resulting ground states, and their gravity duals, remain stable, at least
perturbatively.Despite the complicated field theory dynamics the gravity
solutions have a simple structure. They feature the Ricci-flat non-Kahler
metric on the deformed conifold and the imaginary self-dual three-form flux
accompanied by a constant dilaton.Comment: 27 pages, 6 figures; v2: minor corrections; v3: comments adde
The backreaction of anti-D3 branes on the Klebanov-Strassler geometry
We present the full numerical solution for the 15-dimensional space of
linearized deformations of the Klebanov-Strassler background which preserve the
SU(2) X SU(2) X Z_2 symmetries. We identify within this space the solution
corresponding to anti-D3 branes, (modulo the presence of a certain subleading
singularity in the infrared). All the 15 integration constants of this solution
are fixed in terms of the number of anti-D3 branes, and the solution differs in
the UV from the supersymmetric solution into which it is supposed to decay by a
mode corresponding to a rescaling of the field theory coordinates. Deciding
whether two solutions that differ in the UV by a rescaling mode are dual to the
same theory is involved even for supersymmetric Klebanov-Strassler solutions,
and we explain in detail some of the subtleties associated to this.Comment: 41 pages, 5 figures, LaTe
The Non-SUSY Baryonic Branch: Soft Supersymmetry Breaking of N=1 Gauge Theories
We study a non-supersymmetric deformation of the field theory dual to the
baryonic branch of Klebanov-Strassler. Using a combination of analytical
(series expansions) and numerical methods we construct non-supersymmetric
backgrounds that smoothly interpolate between the desired UV and IR behaviors.
We calculate various observables of the field theory and propose a picture of
soft breaking by gaugino masses that is consistent with the various
calculations on the string side.Comment: 32 pages plus many appendixes. One figur
BPS Wilson Loops on S^2 at Higher Loops
We consider supersymmetric Wilson loops of the variety constructed by
Drukker, Giombi, Ricci, and Trancanelli, whose spatial contours lie on a
two-sphere. Working to second order in the 't Hooft coupling in planar N=4
Supersymmetric Yang-Mills Theory (SYM), we compute the vacuum expectation value
of a wavy-latitude and of a loop composed of two longitudes. We evaluate the
resulting integrals numerically and find that the results are consistent with
the zero-instanton sector calculation of Wilson loops in 2-d Yang-Mills on S^2
performed by Bassetto and Griguolo. We also consider the connected correlator
of two distinct latitudes to third order in the 't Hooft coupling in planar N=4
SYM. We compare the result in the limit where the latitudes become coincident
to a perturbative calculation in 2-d Yang-Mills on S^2 using a light-cone
Wu-Mandelstam-Leibbrandt prescription. We are not able to calculate the SYM
result at the required order in the separation between the latitudes necessary
for a match with 2-d Yang-Mills; the result, however, does not preclude such a
match.Comment: 39 pages, 15 figures. v2 references added, minor cosmetic changes. v3
minor error in eq. (40) corrected. v4 error in coincident limit of correlator
corrected; claims of disagreement with 2-d Yang-Mills retracte
Calibrated Surfaces and Supersymmetric Wilson Loops
We study the dual gravity description of supersymmetric Wilson loops whose
expectation value is unity. They are described by calibrated surfaces that end
on the boundary of anti de-Sitter space and are pseudo-holomorphic with respect
to an almost complex structure on an eight-dimensional slice of AdS_5 x S^5.
The regularized area of these surfaces vanishes, in agreement with field theory
non-renormalization theorems for the corresponding operators.Comment: 28 pages, 2 figure
States of Negative Energy and
We develop a careful definition of energy for nonsupersymmetric warped
product asymptotically solutions which include a nonzero
p-form. In the case of an electric p-form extending along all the AdS
directions, and in particular in the case of self-dual fields like those used
in the Freund-Rubin construction, the Hamiltonian is well defined only if a
particular asymptotic gauge for the p-form is used. Rather surprisingly,
asymptotically this gauge is time dependent, despite the fact the field and
metric are not. We then consider a freely orbifolded and
demonstrate that the standard boundary conditions allow states of arbitrarily
negative energy. The states consist of time symmetric initial data describing
bubbles that are regular up to singularities due to smeared D3-branes. We
discuss the evolution of this data and point out that if the usual boundary
conditions are enforced such bubbles may never reach infinity.Comment: 33 pages, 1 figure, v2: minor corrections, added referenc
Wilson Loops in N=4 SYM and Fermion Droplets
The matrix models which are conjectured to compute the circle Wilson loop and
its correlator with chiral primary operators are mapped onto normal matrix
models. A fermion droplet picture analogous to the well-known one for chiral
primary operators is shown to emerge in the large N limit. Several examples are
computed. We find an interesting selection rule for the correlator of a single
trace Wilson loop with a chiral primary operator. It can be non-zero only if
the chiral primary is in a representation with a single hook. We show that the
expectation value of the Wilson loop in a large representation labelled by a
Young diagram with a single row has a first order phase transition between a
regime where it is identical to a large column representation and a regime
where it is a large wrapping number single trace Wilson loop.Comment: 32 pages, 2 figure
Wilson Loops in Superconformal Chern-Simons Theory and Fundamental Strings in Anti-de Sitter Supergravity Dual
We study Wilson loop operators in three-dimensional, N=6 superconformal
Chern-Simons theory dual to IIA superstring theory on AdS4 x CP3. Novelty of
Wilson loop operators in this theory is that, for a given contour, there are
two linear combinations of Wilson loop transforming oppositely under
time-reversal transformation. We show that one combination is holographically
dual to IIA fundamental string, while orthogonal combination is set to zero. We
gather supporting evidences from detailed comparative study of generalized
time-reversal transformations in both D2-brane worldvolume and ABJM theories.
We then classify supersymmetric Wilson loops and find at most
1/6-supersymmetry. We next study Wilson loop expectation value in planar
perturbation theory. For circular Wilson loop, we find features remarkably
parallel to circular Wilson loop in N=4 super Yang-Mills theory in four
dimensions. First, all odd loop diagrams vanish identically and even loops
contribute nontrivial contributions. Second, quantum corrected gauge and scalar
propagators take the same form as those of N=4 super Yang-Mills theory.
Combining these results, we propose that expectation value of circular Wilson
loop is given by Wilson loop expectation value in pure Chern-Simons theory
times zero-dimensional Gaussian matrix model whose variance is specified by an
interpolating function of `t Hooft coupling. We suggest the function
interpolates smoothly between weak and strong coupling regime, offering new
test ground of the AdS/CFT correspondence.Comment: v1. 34 pages, 11 figures: v2. major revision, all loop proof added 42
pages, 11 figure
On The Inflaton Potential From Antibranes in Warped Throats
We compute the force between a stack of smeared antibranes at the bottom of a
warped throat and a stack of smeared branes at some distance up the throat,
both for anti-D3 branes and for anti-M2 branes. We perform this calculation in
two ways: first, by treating the antibranes as probes in the background sourced
by the branes and second, by treating the branes as probes in the candidate
background sourced by the antibranes. These two very different calculations
yield exactly the same expression for the force, for all values of the
brane-antibrane separation. This indicates that the force between a brane and
an antibrane is not screened in backgrounds where there is positive charge
dissolved in flux, and gives a way to precisely compute the inflaton potential
in certain string cosmology scenarios.Comment: 9 page
Impure Aspects of Supersymmetric Wilson Loops
We study a general class of supersymmetric Wilson loops operator in N = 4
super Yang-Mills theory, obtained as orbits of conformal transformations. These
loops are the natural generalization of the familiar circular Wilson-Maldacena
operator and their supersymmetric properties are encoded into a Killing spinor
that is not pure. We present a systematic analysis of their scalar couplings
and of the preserved supercharges, modulo the action of the global symmetry
group, both in the compact and in the non-compact case. The quantum behavior of
their expectation value is also addressed, in the simplest case of the
Lissajous contours: explicit computations at weak-coupling, through Feynman
diagrams expansion, and at strong-coupling, by means of AdS/CFT correspondence,
suggest the possibility of an exact evaluation.Comment: 40 pages, 4 figure
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