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174
Topological strings in generalized complex space
, 2006
"... A twodimensional topological sigmamodel on a generalized CalabiYau target space X is defined. The model is constructed in BatalinVilkovisky formalism using only a generalized complex structure J and a pure spinor ρ on X. In the present construction the algebra of Qtransformations automatically ..."
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Cited by 37 (1 self)
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A twodimensional topological sigmamodel on a generalized CalabiYau target space X is defined. The model is constructed in BatalinVilkovisky formalism using only a generalized complex structure J and a pure spinor ρ on X. In the present construction the algebra of Qtransformations automatically closes offshell, the model transparently depends only on J, the algebra of observables and correlation functions for topologically trivial maps in genus zero are easily defined. The extended moduli space appears naturally. The familiar action of the twisted N = 2 CFT can be recovered after a gauge fixing. In the open case, we consider an example of generalized deformation of complex structure by a holomorphic Poisson bivector β and recover holomorphic noncommutative Kontsevich ∗product.
D6branes and torsion
"... Abstract: The D6brane spectrum of type IIA vacua based on twisted tori ˜T 6 and RR background fluxes is analyzed. In particular, we compute the torsion factors of Hn(˜T 6, Z) and describe the effect that they have on D6brane physics. For instance, the fact that H3(˜T 6, Z) contains ZN subgroups ex ..."
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Cited by 31 (3 self)
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Abstract: The D6brane spectrum of type IIA vacua based on twisted tori ˜T 6 and RR background fluxes is analyzed. In particular, we compute the torsion factors of Hn(˜T 6, Z) and describe the effect that they have on D6brane physics. For instance, the fact that H3(˜T 6, Z) contains ZN subgroups explains why RR tadpole conditions are affected by geometric fluxes. In addition, the presence of torsional (co)homology shows why some D6brane moduli are lifted, and it suggests how the Dbrane discretum appears in type IIA flux compactifications. Finally, we give a clear, geometrical understanding of the FreedWitten anomaly in the present type IIA setup, and discuss its consequences for the construction of semirealistic flux vacua. Contents 1. Motivation and Summary
Towards Minkowski vacua in type II string compactifications
, 2007
"... We study the vacuum structure of compactifications of type II string theories on orientifolds with SU(3) × SU(3) structure. We argue that generalised geometry enables us to treat these nongeometric compactifications using a supergravity analysis in a way very similar to geometric compactifications ..."
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Cited by 29 (2 self)
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We study the vacuum structure of compactifications of type II string theories on orientifolds with SU(3) × SU(3) structure. We argue that generalised geometry enables us to treat these nongeometric compactifications using a supergravity analysis in a way very similar to geometric compactifications. We find supersymmetric Minkowski vacua with all the moduli stabilised at weak string coupling and all the tadpole conditions satisfied. Generically the value of the moduli fields in the vacuum is parametrically controlled and can be taken to arbitrarily large values.
Generalized complex geometry, generalized branes and the Hitchin sigma model
 JHEP 0503 (2005) 022 [arXiv:hepth/0501062
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Type iia moduli stabilization
 JHEP
"... wati at mit.edu Abstract: We demonstrate that flux compactifications of type IIA string theory can classically stabilize all geometric moduli. For a particular orientifold background, we explicitly construct an infinite family of supersymmetric vacua with all moduli stabilized at arbitrarily large v ..."
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Cited by 27 (0 self)
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wati at mit.edu Abstract: We demonstrate that flux compactifications of type IIA string theory can classically stabilize all geometric moduli. For a particular orientifold background, we explicitly construct an infinite family of supersymmetric vacua with all moduli stabilized at arbitrarily large volume, weak coupling, and small negative cosmological constant. We obtain these solutions from both tendimensional and fourdimensional perspectives. For more general backgrounds, we study the equations for supersymmetric vacua coming from the effective superpotential and show that all geometric moduli can be stabilized by fluxes. We comment on the resulting picture of statistics on the landscape of vacua.
Topological mirror symmetry with fluxes
 JHEP
, 2005
"... Motivated by SU(3) structure compactifications, we show explicitly how to construct half–flat topological mirrors to Calabi–Yau manifolds with NS fluxes. Units of flux are exchanged with torsion factors in the cohomology of the mirror; this is the topological complement of previous differential–geom ..."
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Cited by 26 (1 self)
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Motivated by SU(3) structure compactifications, we show explicitly how to construct half–flat topological mirrors to Calabi–Yau manifolds with NS fluxes. Units of flux are exchanged with torsion factors in the cohomology of the mirror; this is the topological complement of previous differential–geometric mirror rules. The construction modifies explicit SYZ fibrations for compact Calabi–Yaus. The results are of independent interest for SU(3) compactifications. For example one can exhibit explicitly which massive forms should be used for Kaluza–Klein reduction, proving previous conjectures. Formality shows that these forms carry no topological information; this is also confirmed by infrared limits and old classification theorems. 1
On the supergravity formulation of mirror symmetry in generalized CalabiYau manifolds
, 2007
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Extremal Black Hole and Flux Vacua Attractors
, 2007
"... These lectures provide a pedagogical, introductory review of the socalled Attractor Mechanism (AM) at work in two different 4dimensional frameworks: extremal black holes in N = 2 supergravity and N = 1 flux compactifications. In the first case, AM determines the stabilization of scalars at the bla ..."
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Cited by 23 (15 self)
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These lectures provide a pedagogical, introductory review of the socalled Attractor Mechanism (AM) at work in two different 4dimensional frameworks: extremal black holes in N = 2 supergravity and N = 1 flux compactifications. In the first case, AM determines the stabilization of scalars at the black hole event horizon purely in terms of the electric and magnetic charges, whereas in the second context the AM is responsible for the stabilization of the universal axiondilaton and of the (complex structure) moduli purely in terms of the RR and NSNS fluxes. Two equivalent approaches to AM, namely the socalled “criticality conditions ” and “New Attractor ” ones, are analyzed in detail in both frameworks, whose analogies and differences are discussed. Also a stringy analysis of both frameworks (relying on Hodgedecomposition techniques) is performed, respectively considering 2 CY3×T Type IIB compactified on CY3 and its orientifolded version, associated with. Finally, recent Z2 results on the Uduality orbits and moduli spaces of nonBPS extremal black hole attractors in