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61
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 145 (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
Topological sigmamodels with Hflux and twisted generalized complex manifolds
, 2008
"... We study the topological sector of N = 2 sigmamodels with Hflux. It has been known for a long time that the targetspace geometry of these theories is not Kähler and can be described in terms of a pair of complex structures, which do not commute, in general, and are parallel with respect to two di ..."
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Cited by 88 (4 self)
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We study the topological sector of N = 2 sigmamodels with Hflux. It has been known for a long time that the targetspace geometry of these theories is not Kähler and can be described in terms of a pair of complex structures, which do not commute, in general, and are parallel with respect to two different connections with torsion. Recently an alternative description of this geometry was found, which involves a pair of commuting twisted generalized complex structures on the target space. In this paper we define and study the analogues of A and Bmodels for N = 2 sigmamodels with Hflux and show that the results are naturally expressed in the language of twisted generalized complex geometry. For example, the space of topological observables is given by the cohomology of a Lie algebroid associated to one of the two twisted generalized complex structures. We determine the topological scalar product, which endows the algebra of observables with the structure of a Frobenius algebra. We also discuss mirror symmetry for twisted generalized CalabiYau manifolds.
BPS Action and Superpotential for Heterotic String Compactifications with Fluxes
, 2003
"... We consider N = 1 compactifications to four dimensions of heterotic string theory in the presence of fluxes. We show that up to order O (α ′2) the associated action can be written as a sum of squares of BPSlike quantities. In this way we prove that the equations of motion are solved by backgrounds ..."
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Cited by 81 (4 self)
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We consider N = 1 compactifications to four dimensions of heterotic string theory in the presence of fluxes. We show that up to order O (α ′2) the associated action can be written as a sum of squares of BPSlike quantities. In this way we prove that the equations of motion are solved by backgrounds which fulfill the supersymmetry conditions and the Bianchi identities. We also argue for the expression of the related superpotential and discuss the radial modulus
Deformations of generalized calibrations and compact nonKähler manifolds with vanishing first Chern class
, 2002
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Maximally supersymmetric solutions of ten and elevendimensional supergravities
, 2002
"... We classify (up to local isometry) the maximally supersymmetric solutions of the eleven and tendimensional supergravity theories. We find that the AdS solutions, the Hppwaves and the flat space solutions exhaust them. ..."
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Cited by 43 (8 self)
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We classify (up to local isometry) the maximally supersymmetric solutions of the eleven and tendimensional supergravity theories. We find that the AdS solutions, the Hppwaves and the flat space solutions exhaust them.
Killing Spinor Equations In Dimension 7 And Geometry Of Integrable G_2Manifolds
, 2008
"... We compute the scalar curvature of 7dimensional G2manifolds admitting a connection with totally skewsymmetric torsion. We prove the formula for the general solution of the Killing spinor equation and express the Riemannian scalar curvature of the solution in terms of the dilation function and the ..."
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Cited by 40 (0 self)
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We compute the scalar curvature of 7dimensional G2manifolds admitting a connection with totally skewsymmetric torsion. We prove the formula for the general solution of the Killing spinor equation and express the Riemannian scalar curvature of the solution in terms of the dilation function and the NS 3form field. In dimension n = 7 the dilation function involved in the second fermionic string equation has an interpretation as a conformal change of the underlying integrable G2structure into a cocalibrated one of pure type W3.
Compactifications of heterotic strings on nonKähler complex manifolds
 II,” Nucl. Phys. B
"... We continue our study of heterotic compactifications on nonKähler complex manifolds with torsion. We give further evidence of the consistency of the sixdimensional manifold presented earlier and discuss the anomaly cancellation and possible supergravity description for a generic nonKähler complex ..."
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Cited by 30 (11 self)
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We continue our study of heterotic compactifications on nonKähler complex manifolds with torsion. We give further evidence of the consistency of the sixdimensional manifold presented earlier and discuss the anomaly cancellation and possible supergravity description for a generic nonKähler complex manifold using the newly proposed superpotential. The manifolds studied in our earlier papers had zero Euler characteristics. We construct new examples of nonKähler complex manifolds with torsion in lower dimensions, that have nonzero Euler characteristics. Some of these examples are constructed from consistent backgrounds in Ftheory and therefore are solutions to the string equations of motion. We discuss consistency conditions for compactifications of the heterotic string on smooth nonKähler manifolds and illustrate how some results well known for CalabiYau compactifications, including counting the number of generations, apply to the nonKähler case. We briefly address various issues regarding possible phenomenological
HETEROTIC SUPERSYMMETRY, ANOMALY CANCELLATION AND EQUATIONS OF MOTION
, 2009
"... We show that the heterotic supersymmetry (Killing spinor equations) and the anomaly cancellation imply the heterotic equations of motion up to two loops in dimensions five, six, seven, eight if and only if the connection on the tangent bundle is an instanton. For heterotic compactifications in dimen ..."
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Cited by 25 (1 self)
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We show that the heterotic supersymmetry (Killing spinor equations) and the anomaly cancellation imply the heterotic equations of motion up to two loops in dimensions five, six, seven, eight if and only if the connection on the tangent bundle is an instanton. For heterotic compactifications in dimension six this fixes an unique choice of the connection on the tangent bundle in the α′ correction of the anomaly cancellation.