Results 11  20
of
158
Nonperturbative superpotentials in Ftheory and string duality
, 2005
"... We use openclosed string duality between Ftheory on K3 × K3 and type II strings on CY manifolds without branes to study nonperturbative superpotentials in generalized flux compactifications. On the Ftheory side we obtain the full flux potential including D3instanton contributions and show that ..."
Abstract

Cited by 45 (2 self)
 Add to MetaCart
(Show Context)
We use openclosed string duality between Ftheory on K3 × K3 and type II strings on CY manifolds without branes to study nonperturbative superpotentials in generalized flux compactifications. On the Ftheory side we obtain the full flux potential including D3instanton contributions and show that it leads to an explicit and simple realization of the three ingredients of the KKLT model for stringy dS vacua. The D3instanton contribution is highly nontrivial, can be systematically computed including the determinant factors and demonstrates that a particular flux lifts very effectively zero modes on the instanton. On the closed string side, we describe a generalization of the GukovVafaWitten superpotential for type II strings on generalized CY manifolds, depending on all moduli multiplets.
Jumping Through Loops: On Soft Terms from Large Volume Compactifications
 JHEP
, 2007
"... We subject the phenomenologically successful large volume scenario of hepth/0502058 to a first consistency check in string theory. In particular, we consider whether the expansion of the string effective action is consistent in the presence of Dbranes and Oplanes. Due to the noscale structure at ..."
Abstract

Cited by 41 (0 self)
 Add to MetaCart
(Show Context)
We subject the phenomenologically successful large volume scenario of hepth/0502058 to a first consistency check in string theory. In particular, we consider whether the expansion of the string effective action is consistent in the presence of Dbranes and Oplanes. Due to the noscale structure at treelevel, the scenario is surprisingly robust. We compute the modification of soft supersymmetry breaking terms, and find only subleading corrections. We also comment that for largevolume limits of toroidal orientifolds and fibered CalabiYau manifolds the corrections can be more important,
Inflation from warped space
 JHEP
, 2005
"... A long period of inflation can be triggered when the inflaton is held up on the top of a steep potential by the infrared end of a warped space. We first study the field theory description of such a model. We then embed it in the flux stabilized string compactification. Some special effects in the th ..."
Abstract

Cited by 38 (8 self)
 Add to MetaCart
(Show Context)
A long period of inflation can be triggered when the inflaton is held up on the top of a steep potential by the infrared end of a warped space. We first study the field theory description of such a model. We then embed it in the flux stabilized string compactification. Some special effects in the throat reheating process by relativistic branes are discussed. We put all these ingredients into a multithroat brane inflationary scenario. The resulting cosmic string tension Inflation [1–3] provides a natural mechanism for creating the homogeneity and flatness of our observable universe. It also gives an elegant way of generating the perturbations [4–10] which seed the structure formation. In order for the inflation to last sufficiently long and then successfully exit to reheat the universe, the inflaton has to be held up on a potential for
Heterotic Moduli Stabilization with Fractional ChernSimons Invariants
 MODULI STABILIZATION IN THE HETEROTIC/IIB DISCRETUUM
, 2004
"... We show that fractional flux from Wilson lines can stabilize the moduli of heterotic string compactifications on CalabiYau threefolds. We observe that the Wilson lines used in GUT symmetry breaking naturally induce a fractional flux. When combined with a hiddensector gaugino condensate, this gener ..."
Abstract

Cited by 36 (0 self)
 Add to MetaCart
(Show Context)
We show that fractional flux from Wilson lines can stabilize the moduli of heterotic string compactifications on CalabiYau threefolds. We observe that the Wilson lines used in GUT symmetry breaking naturally induce a fractional flux. When combined with a hiddensector gaugino condensate, this generates a potential for the complex structure moduli, Kähler moduli, and dilaton. This potential has a supersymmetric AdS minimum at moderately weak coupling and large volume. Notably, the necessary ingredients for this construction are often present in realistic models. We explore the type IIA dual phenomenon, which involves Wilson lines in D6branes wrapping a threecycle in a CalabiYau, and comment on the nature of the fractional instantons which change the ChernSimons invariant.
Closer towards inflation in string theory,” Phys
 Inflation in realistic Dbrane models,” JHEP 0409, 033 (2004), hepth/0403119 ; A. Buchel
, 2004
"... ..."
(Show Context)
MODELS OF PARTICLE PHYSICS FROM TYPE IIB STRING THEORY AND FTHEORY: A REVIEW
, 2012
"... We review particle physics model building in type IIB string theory and Ftheory. 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 ..."
Abstract

Cited by 33 (4 self)
 Add to MetaCart
We review particle physics model building in type IIB string theory and Ftheory. 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 D3branes at singularities and global models of intersecting D7branes. Much of recent model building work has been in the strongly coupled regime of Ftheory due to the presence of exceptional symmetries which allow for the construction of phenomenologically appealing Grand Unified Theories. We review both local and global Ftheory 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.
Brane Inflation and Cosmic String Tension in Superstring Theory,” arXiv:hepth/0501099
"... Abstract. In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3D3brane inflationary scenario in superstring theory requires ..."
Abstract

Cited by 30 (11 self)
 Add to MetaCart
(Show Context)
Abstract. In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3D3brane inflationary scenario in superstring theory requires
The giant inflaton
, 2002
"... We investigate a new mechanism for realizing slow roll inflation in string theory, based on the dynamics of p antiD3 branes in a class of mildly warped flux compactifications. Attracted to the bottom of a warped conifold throat, the antibranes then cluster due to a novel mechanism wherein the back ..."
Abstract

Cited by 30 (5 self)
 Add to MetaCart
(Show Context)
We investigate a new mechanism for realizing slow roll inflation in string theory, based on the dynamics of p antiD3 branes in a class of mildly warped flux compactifications. Attracted to the bottom of a warped conifold throat, the antibranes then cluster due to a novel mechanism wherein the background flux polarizes in an attempt to screen them. Once they are sufficiently close, the M units of flux cause the antibranes to expand into a fuzzy NS5brane, which for rather generic choices of p/M will unwrap around the geometry, decaying into D3branes via a classical process. We find that the effective potential governing this evolution possesses several epochs that can potentially support slowroll inflation, provided the process can be arranged to take place at a high enough energy scale, of about one or two orders of magnitude below the Planck energy; this scale, however, lies just outside the bounds of our approximations
On the explicit construction and statistics of CalabiYau flux vacua,” hepth/0409215
"... We explicitly construct and study the statistics of flux vacua for type IIB string theory on an orientifold of the CalabiYau hypersurface P 4 [1,1,2,2,6], parametrised by two relevant complex structure moduli. We solve for these moduli and the dilaton field in terms of the set of integers defining ..."
Abstract

Cited by 29 (2 self)
 Add to MetaCart
(Show Context)
We explicitly construct and study the statistics of flux vacua for type IIB string theory on an orientifold of the CalabiYau hypersurface P 4 [1,1,2,2,6], parametrised by two relevant complex structure moduli. We solve for these moduli and the dilaton field in terms of the set of integers defining the 3form fluxes and examine the distribution of vacua. We compare our numerical results with the predictions of the AshokDouglas density det(−R −ω), finding good overall agreement in different regions of moduli space. The number of vacua are found to scale with the distance in flux space. Vacua cluster in the region close to the conifold singularity. Large supersymmetry breaking is more generic but supersymmetric and hierarchical supersymmetry breaking vacua can also be obtained. In particular, the small superpotentials and large dilaton VEVs needed to obtain de Sitter space in a controllable approximation are possible but not generic. We argue that in a general flux compactification, the rank of the gauge group