7,556 research outputs found
Near-flat space limit and Einstein manifolds
We study the near-flat space limit for strings on AdS(5)xM(5), where the
internal manifold M(5) is equipped with a generic metric with U(1)xU(1)xU(1)
isometry. In the bosonic sector, the limiting sigma model is similar to the one
found for AdS(5)xS(5), as the global symmetries are reduced in the most general
case. When M(5) is a Sasaki-Einstein space like T(1,1), Y(p,q) and L(p,q,r),
whose dual CFT's have N=1 supersymmetry, the near-flat space limit gives the
same bosonic sector of the sigma model found for AdS(5)xS(5). This indicates
the generic presence of integrable subsectors in AdS/CFT.Comment: 30 pages, 1 figur
R-charges from toric diagrams and the equivalence of a-maximization and Z-minimization
We conjecture a general formula for assigning R-charges and multiplicities
for the chiral fields of all gauge theories living on branes at toric
singularities. We check that the central charge and the dimensions of all the
chiral fields agree with the information on volumes that can be extracted from
toric geometry. We also analytically check the equivalence between the volume
minimization procedure discovered in hep-th/0503183 and a-maximization, for the
most general toric diagram. Our results can be considered as a very general
check of the AdS/CFT correspondence, valid for all superconformal theories
associated with toric singularities.Comment: 43 pages, 17 figures; minor correction
Killing forms on the five-dimensional Einstein-Sasaki Y(p,q) spaces
We present the complete set of Killing-Yano tensors on the five-dimensional
Einstein-Sasaki Y(p,q) spaces. Two new Killing-Yano tensors are identified,
associated with the complex volume form of the Calabi-Yau metric cone. The
corresponding hidden symmetries are not anomalous and the geodesic equations
are superintegrable.Comment: 10 pages; improved versio
Comments on Anomalies and Charges of Toric-Quiver Duals
We obtain a simple expression for the triangle `t Hooft anomalies in quiver
gauge theories that are dual to toric Sasaki-Einstein manifolds. We utilize the
result and simplify considerably the proof concerning the equivalence of
a-maximization and Z-minimization. We also resolve the ambiguity in defining
the flavor charges in quiver gauge theories. We then compare coefficients of
the triangle anomalies with coefficients of the current-current correlators and
find perfect agreement.Comment: 22 pages, 3 figure
On the pp-wave limit and the BMN structure of new Sasaki-Einstein spaces
We construct the pp-wave string associated with the Penrose limit of
and families of Sasaki-Einstein geometries. We identify
in the dual quiver gauge theories the chiral and the non-chiral operators that
correspond to the ground state and the first excited states. We present an
explicit identification in a prototype model of .Comment: 21 pages, JHEP format, 5 figures, acknowledgement correcte
A QCD analysis of HERA and fixed target structure function data
The parton momentum densities in the proton are obtained from a NLO QCD
analysis of structure functions measured by HERA and fixed target experiments.
The uncertainties in these parton densities, the structure functions and
related cross sections are estimated from the experimental errors, taking into
account all correlations. Standard Model predictions for the charged current
Born cross sections at large x and Q2 are calculated and compared with recent
data from ZEUS.Comment: 4 pages LaTeX, 5 eps figures, uses npb.sty. Presented at DIS99,
Zeuthen, Germany, April 19-23, 199
The Toric Phases of the Y^{p,q} Quivers
We construct all connected toric phases of the recently discovered
quivers and show their IR equivalence using Seiberg duality. We also compute
the R and global U(1) charges for a generic toric phase of .Comment: 14 pages, 3 figure
Strings on the deformed T^{1,1}: giant magnon and single spike solutions
In this paper we find giant magnon and single spike string solutions in a
sector of the gamma-deformed conifold. We examine the dispersion relations and
find a behavior analogous to the undeformed case. The transcendental functional
relations between the conserved charges are shifted by certain gamma-dependent
term. The latter is proportional to the total momentum and thus qualitatively
different from known cases.Comment: 35 pages, no figure
Comments on the non-conformal gauge theories dual to Ypq manifolds
We study the infrared behavior of the entire class of Y(p,q) quiver gauge
theories. The dimer technology is exploited to discuss the duality cascades and
support the general belief about a runaway behavior for the whole family. We
argue that a baryonic classically flat direction is pushed to infinity by the
appearance of ADS-like terms in the effective superpotential. We also study in
some examples the IR regime for the L(a,b,c) class showing that the same
situation might be reproduced in this more general case as well.Comment: 48 pages, 27 figures; updated reference
Zonotopes and four-dimensional superconformal field theories
The a-maximization technique proposed by Intriligator and Wecht allows us to
determine the exact R-charges and scaling dimensions of the chiral operators of
four-dimensional superconformal field theories. The problem of existence and
uniqueness of the solution, however, has not been addressed in general setting.
In this paper, it is shown that the a-function has always a unique critical
point which is also a global maximum for a large class of quiver gauge theories
specified by toric diagrams. Our proof is based on the observation that the
a-function is given by the volume of a three dimensional polytope called
"zonotope", and the uniqueness essentially follows from Brunn-Minkowski
inequality for the volume of convex bodies. We also show a universal upper
bound for the exact R-charges, and the monotonicity of a-function in the sense
that a-function decreases whenever the toric diagram shrinks. The relationship
between a-maximization and volume-minimization is also discussed.Comment: 29 pages, 15 figures, reference added, typos corrected, version
published in JHE
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