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Four-dimensional String Compactifications with D-Branes, Orientifolds and Fluxes
"... This review article provides a pedagogical introduction into various classes of chiral string compactifications to four dimensions with D-branes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct four-dimensional 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 D-branes and fluxes. The main concern is to provide all necessary technical tools to explicitly construct four-dimensional 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 four-dimensional effective action. Finally, we summarize recent attempts to address the
Dynamics of warped compactifications and the shape of the warped landscape
, 2005
"... The dynamics of warped/flux compactifications is studied, including warping effects, providing a firmer footing for investigation of the “landscape.” We present a general formula for the four-dimensional potential of warped compactifications in terms of tendimensional quantities. This allows a syste ..."
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Cited by 77 (2 self)
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The dynamics of warped/flux compactifications is studied, including warping effects, providing a firmer footing for investigation of the “landscape.” We present a general formula for the four-dimensional potential of warped compactifications in terms of tendimensional quantities. This allows a systematic investigation of moduli-fixing effects and potentials for mobile branes. We provide a necessary criterion, “slope-dominance, ” for evading “no-go ” results for de Sitter vacua. We outline the ten-dimensional derivation of the non-perturbative effects that should accomplish this in KKLT examples, and outline a systematic discussion of their corrections. We show that potentials for mobile branes receive generic contributions inhibiting slow-roll inflation. We give a linearized analysis of general scalar perturbations of warped IIB compactifications, revealing new features for both time independent and dependent moduli, and new aspects of the kinetic part of the four-dimensional effective action. The universal Kahler modulus is found not to be a simple scaling of the internal metric, and a prescription is given for defining holomorphic Kahler moduli, including warping effects. In the presence of mobile branes, this
On D3-brane potentials in compactifications with fluxes and wrapped D-branes
- JHEP
, 2006
"... We study the potential governing D3-brane motion in a warped throat region of a string compactification with internal fluxes and wrapped D-branes. If the Kähler moduli of the compact space are stabilized by nonperturbative effects, a D3-brane experiences a force due to its interaction with D-branes ..."
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Cited by 41 (4 self)
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We study the potential governing D3-brane motion in a warped throat region of a string compactification with internal fluxes and wrapped D-branes. If the Kähler moduli of the compact space are stabilized by nonperturbative effects, a D3-brane experiences a force due to its interaction with D-branes wrapping certain four-cycles. We compute this interaction, as a correction to the warped four-cycle volume, using explicit throat backgrounds in supergravity. This amounts to a closed-string 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 four-cycle, 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 D7-branes in a background with D3-branes. Finally, our results have applications to cosmological inflation models in which the inflaton is modeled by a D3-brane
Superstring orientifolds with torsion: O5 orientifolds of torus fibrations and their massless spectra
, 2004
"... Using a “Superstrings with Torsion” type description, we study a class of IIB orientifolds in which spacefilling O5 planes and D5 branes wrap the T² fiber in a warped modification of the product of 4D Minkowski space and a T² fibration. For the case that the base is T⁴, we provide examples that pres ..."
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Cited by 37 (5 self)
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Using a “Superstrings with Torsion” type description, we study a class of IIB orientifolds in which spacefilling O5 planes and D5 branes wrap the T² fiber in a warped modification of the product of 4D Minkowski space and a T² fibration. For the case that the base is T⁴, we provide examples that preserve 4D N = 1, 2, and 3 supersymmetry, both with internal RR flux, and with a combination of internal RR and NS flux. In these examples, the internal geometries admit integrable complex structure; however, the almost complex structure selected by the supersymmetry conditions is nonintegrable in the case that there is NS flux. We indicate explicitly the massless spectrum of gauge fields and moduli in each example. In a previous investigation, this class of orientifolds was studied using T-duality. Here, we extend the previous analysis, first by providing an intrinsic description that does not rely on duality, and then by elaborating on details of the T-duality
MODELS OF PARTICLE PHYSICS FROM TYPE IIB STRING THEORY AND F-THEORY: A REVIEW
, 2012
"... We review particle physics model building in type IIB string theory and F-theory. This is a region in the landscape where in principle many of the key ingredients required for a realistic model of particle physics can be combined successfully. We begin by reviewing moduli stabilisation within this f ..."
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Cited by 33 (4 self)
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We review particle physics model building in type IIB string theory and F-theory. This is a region in the landscape where in principle many of the key ingredients required for a realistic model of particle physics can be combined successfully. We begin by reviewing moduli stabilisation within this framework and its implications for supersymmetry breaking. We then review model building tools and developments in the weakly coupled type IIB limit, for both local D3-branes at singularities and global models of intersecting D7-branes. Much of recent model building work has been in the strongly coupled regime of F-theory due to the presence of exceptional symmetries which allow for the construction of phenomenologically appealing Grand Unified Theories. We review both local and global F-theory model building starting from the fundamental concepts and tools regarding how the gauge group, matter sector and operators arise, and ranging to detailed phenomenological properties explored in the literature.
Numerical Ricci-flat metrics on K3
"... Preprint typeset in JHEP style- HYPER VERSION ..."
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On the supergravity formulation of mirror symmetry in generalized Calabi-Yau manifolds
, 2007
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Monodromy in the CMB: Gravity waves and string inflation,” arXiv:0803.3085 [hep-th]; – 71
- J. High Energy Phys
"... We present a simple mechanism for obtaining large-field inflation, and hence a gravitational wave signature, from string theory compactified on twisted tori. For Nil manifolds, we obtain a leading inflationary potential proportional to φ 2/3 in terms of the canonically normalized field φ, yielding p ..."
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Cited by 20 (1 self)
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We present a simple mechanism for obtaining large-field inflation, and hence a gravitational wave signature, from string theory compactified on twisted tori. For Nil manifolds, we obtain a leading inflationary potential proportional to φ 2/3 in terms of the canonically normalized field φ, yielding predictions for the tilt of the power spectrum and the tensor-to-scalar ratio, ns ≈ 0.98 and r ≈ 0.04 with 60 e-foldings of inflation; we note also the possibility of a variant with a candidate inflaton potential proportional to φ 2/5. The basic mechanism involved in extending the field range – monodromy in D-branes as they move in circles on the manifold – arises in a more general class of compactifications, though our methods for controlling the
Simple de Sitter Solutions
"... We present a framework for de Sitter model building in type IIA string theory, illustrated with specific examples. We find metastable dS minima of the potential for moduli obtained from a compactification on a product of two Nil three-manifolds (which have negative scalar curvature) combined with or ..."
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Cited by 18 (1 self)
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We present a framework for de Sitter model building in type IIA string theory, illustrated with specific examples. We find metastable dS minima of the potential for moduli obtained from a compactification on a product of two Nil three-manifolds (which have negative scalar curvature) combined with orientifolds, branes, fractional Chern-Simons forms, and fluxes. As a discrete quantum number is taken large, the curvature, field strengths, inverse volume, and four dimensional string coupling become parametrically small, and the de Sitter Hubble scale can be tuned parametrically smaller than the scales of the moduli, KK, and winding mode masses. A subtle point in the construction is that although the curvature remains consistently weak, the circle fibers of the nilmanifolds become very small in this limit (though this is avoided in illustrative solutions at modest values of the parameters). In the simplest version of the construction, the heaviest moduli masses are parametrically of the same order as the lightest KK and winding masses. However, we provide a method for separating these marginally overlapping scales, and more generally the underlying supersymmetry of the model protects against large corrections to the lowenergy moduli potential. December
