Results 1  10
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20
Nongeometric Flux Compactifications
, 2006
"... We investigate a simple class of type II string compactifications which incorporate nongeometric “fluxes” in addition to “geometric flux” and the usual Hfield and RR fluxes. These compactifications are nongeometric analogues of the twisted torus. We develop Tduality rules for NSNS geometric and ..."
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Cited by 129 (5 self)
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We investigate a simple class of type II string compactifications which incorporate nongeometric “fluxes” in addition to “geometric flux” and the usual Hfield and RR fluxes. These compactifications are nongeometric analogues of the twisted torus. We develop Tduality rules for NSNS geometric and nongeometric fluxes, which we use to construct a superpotential for the dimensionally reduced fourdimensional theory. The resulting structure is invariant under Tduality, so that the distribution of vacua in the IIA and IIB theories is identical when nongeometric fluxes are included. This gives a concrete framework in which to investigate the possibility that generic string compactifications may be nongeometric in any duality frame. The framework developed in this paper also provides some concrete hints for how mirror symmetry can be generalized to compactifications with arbitrary Hflux, whose mirrors are generically nongeometric.
Cascading RG flows from new SasakiEinstein manifolds
, 2004
"... In important recent developments, new SasakiEinstein spaces Y p,q and conformal gauge theories dual to AdS5 × Y p,q have been constructed. We consider a stack of N D3branes and M wrapped D5branes at the apex of a cone over Y p,q. Replacing the Dbranes by their fluxes, we construct asymptotic sol ..."
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Cited by 54 (6 self)
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In important recent developments, new SasakiEinstein spaces Y p,q and conformal gauge theories dual to AdS5 × Y p,q have been constructed. We consider a stack of N D3branes and M wrapped D5branes at the apex of a cone over Y p,q. Replacing the Dbranes by their fluxes, we construct asymptotic solutions for all p and q in the form of warped products of the cone and R 3,1. We show that they describe cascading RG flows where N decreases logarithmically with the scale. The warp factor, which we determine explicitly, is a function of the radius of the cone and one of the coordinates on Y p,q. We describe the RG cascades in the dual quiver gauge theories, and find an exact agreement between the supergravity and the field theory βfunctions. We also discuss certain dibaryon operators and their dual wrapped D3branes in the conformal case M = 0.
Intersecting brane models of particle physics and the Higgs mechanism
 JHEP 0207
"... Abstract: We analyze a recently constructed class of Dbrane theories with the fermion spectrum of the SM at the intersection of D6branes wrapping a compact toroidal space. We show how the SM Higgs mechanism appears as a brane recombination effect in which the branes giving rise to U(2)L × U(1) rec ..."
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Cited by 35 (8 self)
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Abstract: We analyze a recently constructed class of Dbrane theories with the fermion spectrum of the SM at the intersection of D6branes wrapping a compact toroidal space. We show how the SM Higgs mechanism appears as a brane recombination effect in which the branes giving rise to U(2)L × U(1) recombine into a single brane related to U(1)em. We also show how one can construct D6brane models which respect some supersymmetry at every intersection. These are quasisupersymmetric models of the type introduced in hepth/0201205 which may be depicted in terms of SUSYquivers and may stabilize the hierarchy between the weak scale and a fundamental scale of order 10100 TeV present in low string scale models. Several explicit D6brane models with three generation of quarks and leptons and different SUSYquiver structure are presented. One can prove on general grounds that if one wants to build a (factorizable) D6brane configuration with the SM gauge group and N = 1 SUSY (or quasiSUSY), also a massless (B −L) generator must be initially present in any model. If in addition we insist on left and righthanded fermions respecting the same N = 1 SUSY, the brane configurations are forced to have intersections giving rise to Higgs multiplets, providing for a rationale for the very existence of the SM Higgs sector. JHEP
Bouncing brane cosmologies from warped string compactifications,” arXiv:hepth/0205209
"... We study the cosmology induced on a brane probing a warped throat region in a CalabiYau compactification of type IIB string theory. For the case of a BPS D3brane probing the KlebanovStrassler warped deformed conifold, the cosmology described by a suitable brane observer is a bouncing, spatially f ..."
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Cited by 33 (0 self)
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We study the cosmology induced on a brane probing a warped throat region in a CalabiYau compactification of type IIB string theory. For the case of a BPS D3brane probing the KlebanovStrassler warped deformed conifold, the cosmology described by a suitable brane observer is a bouncing, spatially flat FriedmannRobertsonWalker universe with timevarying Newton’s constant, which passes smoothly from a contracting to an expanding phase. In the KlebanovTseytlin approximation to the KlebanovStrassler solution the cosmology would end with a big crunch singularity. In this sense, the warped deformed conifold provides a string theory resolution of a spacelike singularity in the brane cosmology. The fourdimensional effective action appropriate for a brane observer is a simple scalartensor theory of gravity. In this description of the physics, a bounce is possible because the relevant energymomentum tensor can classically violate the null energy condition. May
A new handle on de Sitter compactifications
 JHEP
, 1998
"... We construct a large new class of de Sitter (and anti de Sitter) vacua of critical string theory from flux compactifications on products of Riemann surfaces. In the construction, the leading effects stabilizing the moduli are perturbative. We show that these effects selfconsistently dominate over s ..."
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Cited by 24 (11 self)
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We construct a large new class of de Sitter (and anti de Sitter) vacua of critical string theory from flux compactifications on products of Riemann surfaces. In the construction, the leading effects stabilizing the moduli are perturbative. We show that these effects selfconsistently dominate over standard estimates for further α ′ and quantum corrections, via tuning available from large flux and brane quantum numbers.
Heterotic flux compactifications and their moduli
, 2006
"... We study supersymmetric compactification to four dimensions with nonzero Hflux in heterotic string theory. The background metric is generically conformally balanced and can be conformally Kähler if the primitive part of the Hflux vanishes. Analyzing the linearized variational equations, we write ..."
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Cited by 21 (3 self)
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We study supersymmetric compactification to four dimensions with nonzero Hflux in heterotic string theory. The background metric is generically conformally balanced and can be conformally Kähler if the primitive part of the Hflux vanishes. Analyzing the linearized variational equations, we write down necessary conditions for the existence of moduli associated with the metric. In a heterotic model that is dual to a IIB compactification on an orientifold, we find the metric moduli in a fixed Hflux background via duality and check that they satisfy the required conditions. We also discuss expressing the conditions for moduli in a fixed flux background using twisted differential operators.
Some thoughts on the quantum theory of stable de Sitter space
"... Preprint typeset in JHEP style. PAPER VERSION hepth/0503066 ..."
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Cited by 16 (3 self)
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Preprint typeset in JHEP style. PAPER VERSION hepth/0503066
Flux Compactifications on Calabiyau Threefolds
, 2004
"... The presence of RR and NS threeform fluxes in type IIB string compactification on a CalabiYau orientifold gives rise to a nontrivial superpotential W for the dilaton and complex structure moduli. This superpotential is computable in terms of the period integrals of the CalabiYau manifold. In this ..."
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Cited by 9 (0 self)
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The presence of RR and NS threeform fluxes in type IIB string compactification on a CalabiYau orientifold gives rise to a nontrivial superpotential W for the dilaton and complex structure moduli. This superpotential is computable in terms of the period integrals of the CalabiYau manifold. In this paper, we present explicit examples of both supersymmetric and nonsupersymmetric solutions to the resulting 4d N = 1 supersymmetric noscale supergravity, including some nonsupersymmetric solutions with relatively small values of W. Our examples arise on orientifolds of the hypersurfaces in WP 4 1,1,1,1,4 and WP 4 1,1,2,2,6. They serve as explicit illustrations of several of the ingredients which have played a role in the recent proposals for constructing de Sitter vacua of string theory.
Enhanced symmetries in multiparameter flux vacua,” hepth/0506245
"... Abstract: We give a construction of type IIB flux vacua with discrete Rsymmetries and vanishing superpotential for hypersurfaces in weighted projective space with any number of moduli. We find that the existence of such vacua for a given space depends on properties of the modular group, and for Fer ..."
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Cited by 4 (0 self)
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Abstract: We give a construction of type IIB flux vacua with discrete Rsymmetries and vanishing superpotential for hypersurfaces in weighted projective space with any number of moduli. We find that the existence of such vacua for a given space depends on properties of the modular group, and for Fermat models can be determined solely by the weights of the projective space. The periods of the geometry do not in general have arithmetic properties, but live in a vector space whose properties are vital to the construction. Contents