7,560 research outputs found
Triangle Anomalies from Einstein Manifolds
The triangle anomalies in conformal field theory, which can be used to
determine the central charge a, correspond to the Chern-Simons couplings of
gauge fields in AdS under the gauge/gravity correspondence. We present a simple
geometrical formula for the Chern-Simons couplings in the case of type IIB
supergravity compactified on a five-dimensional Einstein manifold X. When X is
a circle bundle over del Pezzo surfaces or a toric Sasaki-Einstein manifold, we
show that the gravity result is in perfect agreement with the corresponding
quiver gauge theory. Our analysis reveals an interesting connection with the
condensation of giant gravitons or dibaryon operators which effectively induces
a rolling among Sasaki-Einstein vacua.Comment: 30 pages, 5 figures; published versio
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
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
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
Nehru’s Bandung moment: India and the convening of the 1955 Asian-African conference
This article explores Jawaharlal Nehru’s role in convening the 1955 Bandung Conference. Drawing upon previously embargoed Indian and Western government records, it sheds light on a largely overlooked aspect of Nehru’s Cold War diplomacy. By doing so, it shows that Nehru did not attach, at least initially, much importance to Indonesia’s calls for an Asian-African conference. Only in late 1954 did he show more interest in the Indonesian proposal. Three factors pushed Nehru in this direction: his reluctance to embarrass Indonesia, his concerns about American regional policy and his desire to exploit China’s support for peaceful coexistence. Confronted with renewed regional tensions but able to capitalize on Beijing’s new-found reasonableness, Nehru threw India’s diplomatic weight behind Indonesia’s proposal with the view to furthering his vision of “areas of peace.” Nehru’s “Bandung moment,” however, was short-lived. Although the Bandung Conference appeared to have advanced India’s national interests in the short term, its benefits were more questionable in the long run. In the end, India was unable to tie China down to its regional vision and protect itself against Chinese belligerence. Faced with a mounting Chinese challenge, Nehru’s strategy, centered upon nonaligned peaceful coexistence, manifested all its limitations
From Sasaki-Einstein spaces to quivers via BPS geodesics: Lpqr
The AdS/CFT correspondence between Sasaki-Einstein spaces and quiver gauge
theories is studied from the perspective of massless BPS geodesics. The
recently constructed toric Lpqr geometries are considered: we determine the
dual superconformal quivers and the spectrum of BPS mesons. The conformal
anomaly is compared with the volumes of the manifolds. The U(1)^2_F x U(1)_R
global symmetry quantum numbers of the mesonic operators are successfully
matched with the conserved momenta of the geodesics, providing a test of
AdS/CFT duality. The correspondence between BPS mesons and geodesics allows to
find new precise relations between the two sides of the duality. In particular
the parameters that characterize the geometry are mapped directly to the
parameters used for a-maximization in the field theory. The analysis simplifies
for the special case of the Lpqq models, which are shown to correspond to the
known "generalized conifolds". These geometries can break conformal invariance
through toric deformations of the complex structure.Comment: 30 pages, 8 figures, LaTeX. v2: One more figure. References added,
typos correcte
Baryonic Generating Functions
We show how it is possible to use the plethystic program in order to compute
baryonic generating functions that count BPS operators in the chiral ring of
quiver gauge theories living on the world volume of D branes probing a non
compact CY manifold. Special attention is given to the conifold theory and the
orbifold C^2/Z_2 times C, where exact expressions for generating functions are
given in detail. This paper solves a long standing problem for the
combinatorics of quiver gauge theories with baryonic moduli spaces. It opens
the way to a statistical analysis of quiver theories on baryonic branches.
Surprisingly, the baryonic charge turns out to be the quantized Kahler modulus
of the geometry.Comment: 44 pages, 7 figures; fonts change
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
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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