Related papers: A Classification of Toroidal Orientifold Models
We study stabilization of moduli in the type--IIB superstring theory on the six-dimensional toroidal orientifold $\T^6/\Omega\cdot(-1)^{F_L}\cdot\Z_2$. We consider background space-filling D9-branes wrapped on the orientifold along with…
String compactifications with non-abelian gauge fields localized on D-branes, with background NSNS and RR 3-form fluxes, and with non-trivial warp factors, can naturally exist within T-dual versions of type I string theory. We develop a…
We consider an open-string realisation of $\mathcal{N}=2\to \mathcal{N}=0$ spontaneous breaking of supersymmetry in four-dimensional Minkowski spacetime. It is based on type IIB orientifold theory compactified on $T^2\times…
We discuss the possibility of finding scenarios, within type IIB string theory compactified on Calabi-Yau orientifolds with fluxes, for realizing gauge mediated supersymmetry breaking. We find that while in principle such scenarios are not…
We use the Witten index in the open string sector to determine tadpole charges of orientifold planes and D-branes. As specific examples we consider type I compactifications on Calabi Yau manifolds and noncompact orbifolds. The tadpole…
We compute the flux induced tadpole and superpotential in various type IIB $Z_N$ compact orientifolds in order to study moduli stabilization. We find supersymmetric vacua with $g_s < 1$ and describe brane configurations with cancelled…
We discuss type IIB orientifolds with D-branes, and NSNS and RR field strength fluxes, with D-brane sectors leading to open string spectra with non-abelian gauge symmetry and charged chiral fermions. The closed string field strengths…
Within the context of type I strings, we show the equivalence between BPS D9 branes with internal magnetic fluxes H_i in the three torii and non-BPS D3 branes with inverted internal magnetic fluxes 1/H_i. We then construct new…
We analyse four-dimensional, supersymmetric intersecting D-brane models in a toroidal orientifold background from a statistical perspective. The distribution and correlation of observables, like gauge groups and couplings, are discussed. We…
We consider the propagation of Type I open superstrings on orbifolds with four non-compact dimensions and $N=1$ supersymmetry. In this paper, we concentrate on a non-trivial Z_2xZ_2 example. We show that consistency conditions, arising from…
On the Type IIB toroidal T^6 orientifolds with generic flux compactifications, we conjecture that in generic supsersymmetric Minkowski vacua, at least one of the flux contributions to the seven-brane and D3-brane tadpoles is positive if the…
We study open descendants of non-supersymmetric type IIB asymmetric (freely acting) orbifolds with zero cosmological constant. A generic feature of these models is that supersymmetry remains unbroken on the brane at all mass levels, while…
We explicitly construct A-type orientifolds of supersymmetric Gepner models. In order to reduce the tadpole cancellation conditions to a treatable number we explicitly work out the generic form of the one-loop Klein bottle, annulus and…
We consider non-perturbative six and four dimensional N=1 space-time supersymmetric orientifolds. Some states in such compactifications arise in ``twisted'' open string sectors which lack world-sheet description in terms of D-branes. Using…
The massless spectrum of an orientifold of the IIB string theory is computed and shown to be identical to F theory on the Calabi-Yau threefold with $h_{11}=51$ and $h_{21}=3$. Target space duality is also considered in this model.
We construct new Standard-like models on Type II orientifolds. In Type IIA theory on $\mathbf{T^6/(\Z_2\times \Z_2)}$ orientifold with intersecting D6-branes, we first construct a three-family trinification model where the $U(3)_C\times…
We describe the general geometrical framework of brane world constructions in orientifolds of type IIA string theory with D6-branes wrapping 3-cycles in a Calabi-Yau 3-fold, and point out their immediate phenomenological relevance. These…
We study the introduction of orientifold six-planes in the type IIA brane configurations known as elliptic models. The N=4 SO(n) and $Sp(k)$ theories softly broken to N=2 through a mass for the adjoint hypermultiplet can be realized in this…
We consider non-perturbative six dimensional N=1 space-time supersymmetric orientifolds of Type IIB on K3 with non-trivial NS-NS B-flux. All of these models are non-perturbative in both orientifold and heterotic pictures. Thus, some states…
The embedding of the SM hypercharge into an orientifold gauge group is studied. Possible embeddings are classified, and a systematic construction of bottom-up configurations and top-down orientifold vacua is achieved, solving the tadpole…