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173
Brane/Flux Annihilation and the String Dual of a NonSupersymmetric Field Theory
, 2006
"... We consider the dynamics of p antiD3 branes inside the KlebanovStrassler geometry, the deformed conifold with M units of RR 3form flux around the S 3. We find that for p << M the system relaxes to a nonsupersymmetric NS 5brane “giant graviton ” configuration, which is classically stable, b ..."
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Cited by 170 (18 self)
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We consider the dynamics of p antiD3 branes inside the KlebanovStrassler geometry, the deformed conifold with M units of RR 3form flux around the S 3. We find that for p << M the system relaxes to a nonsupersymmetric NS 5brane “giant graviton ” configuration, which is classically stable, but quantum mechanically can tunnel to a nearby supersymmetric vacuum with M −p D3 branes. This decay mode is exponentially suppressed and proceeds via the nucleation of an NS 5brane bubble wall. We propose a dual field theory interpretation of the decay as the transition between a nonsupersymmetric “baryonic” branch and a supersymmetric “mesonic” branch of the corresponding SU(2M − p) × SU(M − p) low energy gauge theory. The NS 5brane tunneling process also provides a simple visualization of the The search for calculable and nontrivial nonsupersymmetric string vacua remains a problem of basic interest in string theory. In the context of AdS/CFT duality [1], this is related to the construction of gravitational “antiholographic” descriptions for nonsupersymmetric 4d quantum gauge theories. Here, we describe the construction of a simple nonsupersymmetric
Moduli Stabilization from Fluxes in a Simple IIB Orientifold
, 2002
"... We study novel type IIB compactifications on the T 6 /Z2 orientifold. This geometry arises in the Tdual description of Type I theory on T 6, and one normally introduces 16 spacefilling D3branes to cancel the RR tadpoles. Here, we cancel the RR tadpoles either partially or fully by turning on thre ..."
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Cited by 149 (10 self)
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We study novel type IIB compactifications on the T 6 /Z2 orientifold. This geometry arises in the Tdual description of Type I theory on T 6, and one normally introduces 16 spacefilling D3branes to cancel the RR tadpoles. Here, we cancel the RR tadpoles either partially or fully by turning on threeform flux in the compact geometry. The resulting (super)potential for moduli is calculable. We demonstrate that one can find many examples of N = 1 supersymmetric vacua with greatly reduced numbers of moduli in this system. A few examples with N> 1 supersymmetry or complete supersymmetry breaking are also discussed.
Fourdimensional String Compactifications with DBranes, Orientifolds and Fluxes
"... This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with Dbranes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct fourdimensional orientifold vacua, with the final aim to ..."
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Cited by 147 (18 self)
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This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with Dbranes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct fourdimensional orientifold vacua, with the final aim to come as close as possible to the supersymmetric Standard Model. Furthermore, we outline the available methods to derive the resulting fourdimensional effective action. Finally, we summarize recent attempts to address the
The effective action of type IIA CalabiYau orientifolds
"... The N = 1 effective action for generic type IIA CalabiYau orientifolds in the presence of background fluxes is computed from a KaluzaKlein reduction. The Kähler potential, the gauge kinetic functions and the fluxinduced superpotential are determined in terms of geometrical data of the CalabiYau ..."
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Cited by 95 (6 self)
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The N = 1 effective action for generic type IIA CalabiYau orientifolds in the presence of background fluxes is computed from a KaluzaKlein reduction. The Kähler potential, the gauge kinetic functions and the fluxinduced superpotential are determined in terms of geometrical data of the CalabiYau orientifold and the background fluxes. The moduli space is found to be a Kähler subspace of the N = 2 moduli space and shown to coincide with the moduli space arising in compactification of Mtheory on a specific class of G2 manifolds. The superpotential depends on all geometrical moduli and vanishes at leading order when background fluxes are turned off. The N = 1 chiral coordinates linearize the appropriate instanton actions such that instanton effects can lead to holomorphic corrections of the superpotential. Mirror symmetry between type IIA and type IIB orientifolds is shown to hold at the level of the effective action in the large volume – large complex structure limit.
Duality twists, orbifolds, and fluxes
 JHEP
"... We investigate compactifications with duality twists and their relation to orbifolds and compactifications with fluxes. Inequivalent compactifications are classified by conjugacy classes of the Uduality group and result in gauged supergravities in lower dimensions with nontrivial ScherkSchwarz pot ..."
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Cited by 92 (5 self)
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We investigate compactifications with duality twists and their relation to orbifolds and compactifications with fluxes. Inequivalent compactifications are classified by conjugacy classes of the Uduality group and result in gauged supergravities in lower dimensions with nontrivial ScherkSchwarz potentials on the moduli space. For certain twists, this mechanism is equivalent to introducing internal fluxes but is more general and can be used to stabilize some of the moduli. We show that the potential has stable minima with zero energy precisely at the fixed points of the twist group. In string theory, when the twist belongs to the Tduality group, the theory at the minimum has an exact CFT description as an orbifold. We also discuss more general twists by nonperturbative Uduality transformations. October
SU (3) × SU (3) compactification and mirror duals of magnetic fluxes
, 2009
"... This paper analyses type II string theories in backgrounds which admit an SU(3)×SU(3) structure. Such backgrounds are designed to linearly realize eight out of the original 32 supercharges and as a consequence the lowenergy effective action can be written in terms of couplings which are closely rel ..."
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Cited by 65 (3 self)
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This paper analyses type II string theories in backgrounds which admit an SU(3)×SU(3) structure. Such backgrounds are designed to linearly realize eight out of the original 32 supercharges and as a consequence the lowenergy effective action can be written in terms of couplings which are closely related to the couplings of fourdimensional N = 2 theories. This generalizes the previously studied case of SU(3) backgrounds in that the left and rightmoving sector each have a different globally defined spinor. Given a truncation to a finite number of modes, these backgrounds lead to a conventional fourdimensional lowenergy effective theory. The results are manifestly mirror symmetric and give terms corresponding to the mirror dual couplings of CalabiYau compactifications with magnetic fluxes. It is argued, however, that generically such backgrounds are nongeometric and hence the supergravity analysis is not strictly valid. Remarkably, the naive generalization of the geometrical expressions nonetheless appears to give the correct lowenergy effective theory.
Moduli Stabilisation versus Chirality for MSSM like Type
 IIB Orientifolds,” JHEP 01 (2008) 058
"... We investigate the general question of implementing a chiral MSSM like Dbrane sector in Type IIB orientifold models with complete moduli stabilisation via Fterms induced by fluxes and spacetime instantons, respectively gaugino condensates. The prototype examples are the KKLT and the socalled lar ..."
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Cited by 62 (8 self)
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We investigate the general question of implementing a chiral MSSM like Dbrane sector in Type IIB orientifold models with complete moduli stabilisation via Fterms induced by fluxes and spacetime instantons, respectively gaugino condensates. The prototype examples are the KKLT and the socalled large volume compactifications. We show that the ansatz of first stabilising all moduli via Fterms and then introducing the Standard Model module is misleading, as a chiral sector notoriously influences the structure of nonperturbative effects and induces a Dterm potential. Focusing for concreteness on the large volume scenario, we work out the geometry of the swisscheese type CalabiYau manifold IP [1,3,3,3,5][15] (3,75) and analyse whether controllable and phenomenologically acceptable Kähler moduli stabilisation can occur by the combination of F and Dterms. Contents
Realistic Dbrane Models on Warped Throats: Fluxes, Hierarchies and Moduli Stabilization,” hepth/0312051; 27 Cascales and
 Chiral 4d N = 1 String Vacua with DBranes and NSNS and RR Fluxes,” JHEP 0305 (2003) 011, hepth/0303024
"... Abstract: We describe the construction of string theory models with semirealistic spectrum in a sector of (anti) D3branes located at an orbifold singularity at the bottom of a highly warped throat geometry, which is a generalisation of the KlebanovStrassler deformed conifold. These models realise ..."
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Cited by 56 (10 self)
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Abstract: We describe the construction of string theory models with semirealistic spectrum in a sector of (anti) D3branes located at an orbifold singularity at the bottom of a highly warped throat geometry, which is a generalisation of the KlebanovStrassler deformed conifold. These models realise the RandallSundrum proposal to naturally generate the Planck/electroweak hierarchy in a concrete string theory embedding, and yielding interesting chiral open string spectra. We describe examples with Standard Model gauge group (or leftright symmetric extensions) and three families of SM fermions, with correct quantum numbers including hypercharge. The dilaton and complex structure moduli of the geometry are stabilised by the 3form fluxes required to build the throat. We describe diverse issues concerning the stabilisation of geometric Kähler moduli, like blowup modes of the orbifold singularities, via D term potentials and gauge theory nonperturbative effects, like gaugino condensation. This local geometry, once embedded in a full compactification, could give rise to models with all moduli stabilised, and with the potential to lead to de Sitter vacua. Issues of gauge unification, proton stability, supersymmetry breaking
Enumerating Flux Vacua with Enhanced Symmetries
, 2004
"... We study properties of flux vacua in type IIB string theory in several simple but illustrative models. We initiate the study of the relative frequencies of vacua with vanishing superpotential W = 0 and with certain discrete symmetries. For the models we investigate we also compute the overall rate o ..."
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Cited by 52 (7 self)
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We study properties of flux vacua in type IIB string theory in several simple but illustrative models. We initiate the study of the relative frequencies of vacua with vanishing superpotential W = 0 and with certain discrete symmetries. For the models we investigate we also compute the overall rate of growth of the number of vacua as a function of the D3brane charge associated to the fluxes, and the distribution of vacua on the moduli space. The latter two questions can also be addressed by the statistical theory developed by Ashok, Denef and Douglas, and our results are in good agreement with their predictions. Analysis of the first two questions requires methods which are more numbertheoretic in nature. We develop some elementary techniques of this type, which are based on arithmetic properties of the periods of the compactification geometry at the points in moduli space where the flux vacua are located.