Results 11  20
of
70
MSSM with Soft SUSY Breaking Terms from D7–Branes with Fluxes
, 2004
"... We discuss the structure of the soft supersymmetry breaking terms in a MSSM like model, which can be derived from D7–branes with chiral matter fields from 2–form f–fluxes and supersymmetry breaking from ..."
Abstract

Cited by 44 (7 self)
 Add to MetaCart
We discuss the structure of the soft supersymmetry breaking terms in a MSSM like model, which can be derived from D7–branes with chiral matter fields from 2–form f–fluxes and supersymmetry breaking from
The effective action of N = 1 CalabiYau orientifolds
, 2004
"... We determine the N = 1 low energy effective action for compactifications of type IIB string theory on compact CalabiYau orientifolds in the presence of background fluxes from a KaluzaKlein reduction. The analysis is performed for CalabiYau threefolds which admit an isometric and holomorphic invol ..."
Abstract

Cited by 39 (6 self)
 Add to MetaCart
We determine the N = 1 low energy effective action for compactifications of type IIB string theory on compact CalabiYau orientifolds in the presence of background fluxes from a KaluzaKlein reduction. The analysis is performed for CalabiYau threefolds which admit an isometric and holomorphic involution. We explicitly compute the Kähler potential, the superpotential and the gauge kinetic functions and check the consistency with N = 1 supergravity. We find a new class of noscale Kähler potentials and show that their structure can be best understood in terms of a dual formulation where some of the chiral multiplets are replaced by linear multiplets. For O3 and O7planes the scalar potential is expressed in terms of a superpotential while for O5 and O9planes also a Dterm and a massive linear multiplet can be present. The relation with the associated Ftheory compactifications is briefly discussed. In recent years it became clear that string theory is not only a theory of fundamental strings but also contains higherdimensional extended objects such as Dbranes and orientifold
More Dual Fluxes and Moduli Fixing
, 2006
"... We generalize the recent proposal that invariance under Tduality leads to additional nongeometric fluxes required so that superpotentials in type IIA and type IIB orientifolds match. We show that invariance under type IIB Sduality requires the introduction of a new set of fluxes leading to further ..."
Abstract

Cited by 37 (3 self)
 Add to MetaCart
We generalize the recent proposal that invariance under Tduality leads to additional nongeometric fluxes required so that superpotentials in type IIA and type IIB orientifolds match. We show that invariance under type IIB Sduality requires the introduction of a new set of fluxes leading to further superpotential terms. We find new classes of N=1 supersymmetric Minkowski vacua based on type IIB toroidal orientifolds in which not only dilaton and complex moduli but also Kähler moduli are fixed. The chains of dualities relating type II orientifolds to heterotic and Mtheory compactifications suggests the existence of yet further flux degrees of freedom. Restricting to a particular type IIA/IIB or heterotic compactification only some of these degrees of freedom have a simple perturbative and/or geometric interpretation.
Warped strings: Selfdual flux and contemporary compactifications
"... String theory is a leading candidate for the quantum theory of gravitation and is the only serious unified theory of all the forces of physics. Additionally, string theory seems to be mathematically unique, and it is possible that all the parameters of physics could be determined by the dynamics of ..."
Abstract

Cited by 34 (3 self)
 Add to MetaCart
(Show Context)
String theory is a leading candidate for the quantum theory of gravitation and is the only serious unified theory of all the forces of physics. Additionally, string theory seems to be mathematically unique, and it is possible that all the parameters of physics could be determined by the dynamics of string theory. However, there are two intertwined problems. First is that string theory requires ten dimensions for mathematical consistency, so six must be compact or otherwise decoupled from the physics we observe. Also, there exist many different ground states of string theory, so it is difficult to make predictions that are generic to string theory. Therefore, it is crucial to gain a broad understanding of all the string theory vacua, particularly those compactified to four dimensions. In recent years, our understanding of string theory compactifications has expanded greatly to include many new classes of solutions. In this dissertation, I discuss type IIB string compactifications in which the threeform field strengths satisfy a selfduality condition on the internal manifold. I
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 ..."
Abstract

Cited by 31 (3 self)
 Add to MetaCart
(Show Context)
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
Building MSSM Flux Vacua
, 2008
"... We construct N = 1 and N = 0 chiral fourdimensional vacua of flux compactification in Type IIB string theory. These vacua have the common features that they are free of tadpole instabilities (both NSNS and RR) even for models with N = 0 supersymmetry. In addition, the dilaton/complex structure mod ..."
Abstract

Cited by 30 (4 self)
 Add to MetaCart
We construct N = 1 and N = 0 chiral fourdimensional vacua of flux compactification in Type IIB string theory. These vacua have the common features that they are free of tadpole instabilities (both NSNS and RR) even for models with N = 0 supersymmetry. In addition, the dilaton/complex structure moduli are stabilised and the supergravity background metric is warped. We present an example in which the low energy spectrum contains the MSSM spectrum with three generations of chiral matter. In the N = 0 models, the background fluxes which stabilise the moduli also induce soft supersymmetry breaking terms in the gauge and chiral sectors of the theory, while satisfying the equation of motion. We also discuss some phenomenological features of these three generation MSSM flux vacua. Our techniques apply to other closed string backgrounds as well and, in fact, also allow to find new N = 1 Dbrane models which were believed not to exist. Finally, we discuss in detail the consistency conditions of these flux compactifications. Cancellation of Ktheory charges puts additional constraints on the consistency of the models, which render some chiral Dbrane models in the literature inconsistent.
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 ..."
Abstract

Cited by 24 (11 self)
 Add to MetaCart
(Show Context)
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.
SUSYbreaking soft terms in a MSSM magnetized D7brane model,” JHEP 0503, 040 (2005) [arXiv:hepth/0412150]; M.P.G. del Moral, “A new mechanism of Kahler moduli stabilization in type IIB theory,” arXiv:hepth/0506116
"... We compute the SUSYbreaking soft terms in a magnetized D7brane model with MSSMlike spectrum, under the general assumption of nonvanishing auxiliary fields of the dilaton and Kähler moduli. As a particular scenario we discuss SUSY breaking triggered by ISD or IASD 3form fluxes. 1 On leave from D ..."
Abstract

Cited by 23 (2 self)
 Add to MetaCart
(Show Context)
We compute the SUSYbreaking soft terms in a magnetized D7brane model with MSSMlike spectrum, under the general assumption of nonvanishing auxiliary fields of the dilaton and Kähler moduli. As a particular scenario we discuss SUSY breaking triggered by ISD or IASD 3form fluxes. 1 On leave from Departamento de Física, Facultad de Ciencias, Universidad Central de Venezuela, A.P.
Branes on generalized calibrated submanifolds
 JHEP 0411 (2004) 083 [arXiv:hepth/0407132
"... We extend previous results on generalized calibrations to describe supersymmetric branes in supergravity backgrounds with diverse fields turned on, and provide several new classes of examples. As an important application, we show that supersymmetric Dbranes in compactifications with field strength ..."
Abstract

Cited by 22 (1 self)
 Add to MetaCart
(Show Context)
We extend previous results on generalized calibrations to describe supersymmetric branes in supergravity backgrounds with diverse fields turned on, and provide several new classes of examples. As an important application, we show that supersymmetric Dbranes in compactifications with field strength fluxes, and on SU(3)structure spaces, wrap generalized calibrated submanifolds, defined by simple conditions in terms of the underlying globally defined, but nonclosed, 2 and 3forms. We provide examples where the geometric moduli of Dbranes (for instance D7branes in 3form flux configurations) are lifted by the generalized calibration condition. In addition, we describe supersymmetric D6branes on generalized calibrated 3submanifolds of halfflat manifolds, which provide the mirror of Btype Dbranes in IIB CY compactifications with 3form fluxes. Supersymmetric sets of such Dbranes carrying no homology charges are mirror to supersymmetric sets of Dbranes which are homologically nontrivial, but trivial in Ktheory. As an additional application, we describe models with chiral gauge sectors, realized in terms of generalized calibrated brane box configurations of NS and D5branes, which are supersymmetric but carry no charges, so that no orientifold planes are required in the