Results 1  10
of
70
Gauge theories from toric geometry and brane tilings
, 2005
"... We provide a general set of rules for extracting the data defining a quiver gauge theory from a given toric Calabi–Yau singularity. Our method combines information from the geometry and topology of Sasaki–Einstein manifolds, AdS/CFT, dimers, and brane tilings. We explain how the field content, quan ..."
Abstract

Cited by 147 (25 self)
 Add to MetaCart
(Show Context)
We provide a general set of rules for extracting the data defining a quiver gauge theory from a given toric Calabi–Yau singularity. Our method combines information from the geometry and topology of Sasaki–Einstein manifolds, AdS/CFT, dimers, and brane tilings. We explain how the field content, quantum numbers, and superpotential of a superconformal gauge theory on D3–branes probing a toric Calabi–Yau singularity can be deduced. The infinite family of toric singularities with known horizon Sasaki–Einstein manifolds La,b,c is used to illustrate these ideas. We construct the corresponding quiver gauge theories, which may be fully specified by giving a tiling of the plane by hexagons with certain gluing rules. As checks of this construction, we perform amaximisation as well as Zminimisation to compute the exact Rcharges of an arbitrary such quiver. We also examine a number of examples in detail, including the infinite subfamily La,b,a, whose smallest member is the
SasakiEinstein manifolds and volume minimisation
, 2006
"... We study a variational problem whose critical point determines the Reeb vector field for a Sasaki–Einstein manifold. This extends our previous work on Sasakian geometry by lifting the condition that the manifolds are toric. We show that the Einstein–Hilbert action, restricted to a space of Sasakian ..."
Abstract

Cited by 112 (7 self)
 Add to MetaCart
We study a variational problem whose critical point determines the Reeb vector field for a Sasaki–Einstein manifold. This extends our previous work on Sasakian geometry by lifting the condition that the manifolds are toric. We show that the Einstein–Hilbert action, restricted to a space of Sasakian metrics on a link L in a Calabi–Yau cone M, is the volume functional, which in fact is a function on the space of Reeb vector fields. We relate this function both to the Duistermaat– Heckman formula and also to a limit of a certain equivariant index on M that counts holomorphic functions. Both formulae may be evaluated by localisation. This leads to a general formula for the volume function in terms of topological fixed point data. As a result we prove that the volume of any Sasaki–Einstein manifold, relative to that of the round sphere, is always an algebraic number. In complex dimension n = 3 these results provide, via AdS/CFT, the geometric counterpart of a–maximisation in four dimensional superconformal field theories. We also show that our variational problem dynamically sets to zero the Futaki
Nonsupersymmetric metastable vacua from brane configurations
 JHEP
, 2007
"... Abstract: We construct configurations of NS, D4, and D6branes in type IIA string theory, realizing the recently discussed nonsupersymmetric metastable minimum of 4d N = 1 SU(Nc) superYangMills theories with massive flavors. We discuss their lift to Mtheory and the mechanism of pseudomoduli ..."
Abstract

Cited by 61 (0 self)
 Add to MetaCart
(Show Context)
Abstract: We construct configurations of NS, D4, and D6branes in type IIA string theory, realizing the recently discussed nonsupersymmetric metastable minimum of 4d N = 1 SU(Nc) superYangMills theories with massive flavors. We discuss their lift to Mtheory and the mechanism of pseudomoduli stabilization. We extend the construction to many other examples of metastable minima, including the SO/Sp theories, SU(Nc) with matter in twoindex tensor representations, and to a chiral gauge theory.
Stringy instantons and quiver gauge theories,” JHEP 0705
, 2007
"... We explore contributions to the 4D effective superpotential which arise from Euclidean D3 branes (“instantons”) that intersect spacefilling Dbranes. These effects can perturb the effective field theory on the spacefilling branes by nontrivial operators composed of charged matter fields, changing ..."
Abstract

Cited by 54 (6 self)
 Add to MetaCart
(Show Context)
We explore contributions to the 4D effective superpotential which arise from Euclidean D3 branes (“instantons”) that intersect spacefilling Dbranes. These effects can perturb the effective field theory on the spacefilling branes by nontrivial operators composed of charged matter fields, changing the vacuum structure in a qualitative way in some examples. Our considerations are exemplified throughout by a careful study of a fractional brane configuration on a del Pezzo surface. September
Fractional Branes and Dynamical Supersymmetry Breaking
, 2005
"... We study the dynamics of fractional branes at toric singularities, including cones over del Pezzo surfaces and the recently constructed Y p,q theories. We find that generically the field theories on such fractional branes show dynamical supersymmetry breaking, due to the appearance of nonperturba ..."
Abstract

Cited by 43 (6 self)
 Add to MetaCart
We study the dynamics of fractional branes at toric singularities, including cones over del Pezzo surfaces and the recently constructed Y p,q theories. We find that generically the field theories on such fractional branes show dynamical supersymmetry breaking, due to the appearance of nonperturbative superpotentials. In special cases, one recovers the known cases of supersymmetric infrared behaviors, associated to SYM confinement (mapped to complex deformations of the dual geometries, in the gauge/string correspondence sense) or N = 2 fractional branes. In the supersymmetry breaking cases, when the dynamics of closed string moduli at the singularity is included, the theories show a runaway behavior (involving moduli such as FI terms or equivalently dibaryonic operators), rather than stable nonsupersymmetric minima. We comment on the implications of this gauge theory behavior for the infrared smoothing of the dual warped throat solutions with 3form fluxes, describing duality cascades ending in such field theories. We finally provide a description of the different fractional branes in the recently introduced brane tiling configurations.
On D3brane potentials in compactifications with fluxes and wrapped Dbranes
 JHEP
, 2006
"... We study the potential governing D3brane motion in a warped throat region of a string compactification with internal fluxes and wrapped Dbranes. If the Kähler moduli of the compact space are stabilized by nonperturbative effects, a D3brane experiences a force due to its interaction with Dbranes ..."
Abstract

Cited by 41 (4 self)
 Add to MetaCart
(Show Context)
We study the potential governing D3brane motion in a warped throat region of a string compactification with internal fluxes and wrapped Dbranes. If the Kähler moduli of the compact space are stabilized by nonperturbative effects, a D3brane experiences a force due to its interaction with Dbranes wrapping certain fourcycles. We compute this interaction, as a correction to the warped fourcycle volume, using explicit throat backgrounds in supergravity. This amounts to a closedstring channel computation of the loop corrections to the nonperturbative superpotential that stabilizes the volume. We demonstrate for warped conical spaces that the superpotential correction is given by the embedding equation specifying the wrapped fourcycle, in agreement with the general form proposed by Ganor. Our approach automatically provides a solution to the problem of defining a holomorphic gauge coupling on wrapped D7branes in a background with D3branes. Finally, our results have applications to cosmological inflation models in which the inflaton is modeled by a D3brane
The unwarped, resolved, deformed conifold: fivebranes and the baryonic branch of the KlebanovStrassler theory
, 2009
"... ..."
Gauge  mediated supersymmetry breaking in string compactifications
 JHEP
"... We provide string theory examples where a toy model of a SUSY GUT or the MSSM is embedded in a compactification along with a gauge sector which dynamically breaks supersymmetry. We argue that by changing microscopic details of the model (such as precise choices of flux), one can arrange for the domi ..."
Abstract

Cited by 22 (1 self)
 Add to MetaCart
(Show Context)
We provide string theory examples where a toy model of a SUSY GUT or the MSSM is embedded in a compactification along with a gauge sector which dynamically breaks supersymmetry. We argue that by changing microscopic details of the model (such as precise choices of flux), one can arrange for the dominant mediation mechanism transmitting SUSY breaking to the Standard Model to be either gravity mediation or gauge mediation. Systematic improvement of such examples may lead to topdown models incorporating a solution to the SUSY flavor problem.
Towards supergravity duals of chiral symmetry breaking in SasakiEinstein cascading quiver theories
, 2005
"... We construct a first order deformation of the complex structure of the cone over SasakiEinstein spaces Y p,q and check supersymmetry explicitly. This space is a central element in the holographic dual of chiral symmetry breaking for a large class of cascading quiver theories. We discuss a solution ..."
Abstract

Cited by 21 (3 self)
 Add to MetaCart
(Show Context)
We construct a first order deformation of the complex structure of the cone over SasakiEinstein spaces Y p,q and check supersymmetry explicitly. This space is a central element in the holographic dual of chiral symmetry breaking for a large class of cascading quiver theories. We discuss a solution describing a stack of N D3 branes and M fractional D3 branes at the tip of the deformed spaces.
Toric SasakiEinstein manifolds and Heun Equations
, 2006
"... Symplectic potentials are presented for a wide class of five dimensional toric SasakiEinstein manifolds, including L a,b,c which was recently constructed by Cvetič et al. The spectrum of the scalar Laplacian on L a,b,c is also studied. The eigenvalue problem leads to two Heun’s differential equatio ..."
Abstract

Cited by 21 (0 self)
 Add to MetaCart
Symplectic potentials are presented for a wide class of five dimensional toric SasakiEinstein manifolds, including L a,b,c which was recently constructed by Cvetič et al. The spectrum of the scalar Laplacian on L a,b,c is also studied. The eigenvalue problem leads to two Heun’s differential equations and the exponents at regular singularities are directly related to the toric data. By combining knowledge of the explicit symplectic potential and the exponents, we show that the ground states, or equivalently holomorphic functions, have onetoone correspondence with the integral lattice points in the convex polyhedral cone. The scaling dimensions of the holomorphic functions are simply given by the scalar products of the Reeb vector and the integral vectors, which are consistent with Rcharges of the BPS states in the dual quiver gauge theories.