Related papers: D=4,N=1, Type IIB Orientifolds
The cancellation of U(1)-gauge and U(1)-gravitational anomalies in certain D=4 N=1 Type IIB orientifolds is analyzed in detail, from a string theory point of view. We verify the proposal that these anomalies are cancelled by a Green-Schwarz…
We study type IIB orientifolds on T^{2d}/Z_N with supersymmetry broken by the compactification. We determine tadpole cancellation conditions including anti-branes and considering different actions for the parity Omega. Using these…
Based on the twisted R-R tadpole cancellation conditions at the singularities of D=4 Type IIB orbifold $T^6/ Z_3$, we propose a new bottom-up approach to embed standard model with three generations into string theory.
Compact Type IIB D=4, N=1 orientifolds have certain U(1) sigma model symmetries at the level of the effective Lagrangian. These symmetries are generically anomalous. We study the particular case of $Z_N$ orientifolds and find that these…
Supersymmetric orientifolds of four dimensional Gepner Models are constructed in a systematic way. For all levels of the Gepner model being odd the generic expression for both the A-type and the B-type Klein bottle amplitude is derived. The…
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…
In this paper we study the N=1 supersymmetric field theories realized on the world-volume of type IIB D3-branes sitting at orientifolds of non-orbifold singularities (conifold and generalizations). Several chiral models belong to this…
We discuss some Z_N^L x Z_N^R orbifold compactifications of the type IIB superstring to D= 4,6 dimensions and their type I descendants. Although the Z_N^L x Z_N^R generators act asymmetrically on the chiral string modes, they result into…
We calculate the tadpole equations and their solutions for a class of four-dimensional orientifolds with orbifold group Z_N X Z_M, and we present the massless bosonic spectra of these models. Surprisingly we find no consistent solutions for…
We construct type IIA orientifolds on T6/(Z2 x Z2) which admit non factorisable lattices. We describe a method to deal with this kind of configurations and discuss how the compactification lattice affects the tadpole cancellation…
We construct N=1 supersymmetric four-dimensional orientifolds of type IIA on T^6/(Z_2 x Z_2) with D6-branes intersecting at angles. The use of D6-branes not fully aligned with the O6-planes in the model allows for a construction of many…
We study the cancellation of U(1) anomalies in Type I and Type IIB D=4, N=1 string vacua. We first consider the case of compact toroidal $Z_N$ Type IIB orientifolds and then proceed to the non-compact case of Type IIB D3 branes at orbifold…
In tensor products of a left-right symmetric CFT, one can define permutation orientifolds by combining orientation reversal with involutive permutation symmetries. We construct the corresponding crosscap states in general rational CFTs and…
We construct anomaly free non-supersymmetric large N gauge theories from orientifolds of Type IIB on C^3/G orbifolds. In particular, massless as well as tachyonic one-loop tadpoles are cancelled in these models. This is achieved by starting…
We give a complete classification of T6/[Z(2)xZ(2M)xOmegaR] orientifolds on factorisable tori and rigid D6-branes on them. The analysis includes the supersymmetry, RR tadpole cancellation and K-theory conditions and complete massless open…
We present orientifold models of type IIA string theory with D8-branes compactified on a two torus times a four dimensional orbifold. The orientifold group is chosen such that one coordinate of the two torus is reversed when applying…
We construct boundary state and crosscap state in D=4,N=1 type-IIB Z_N orientifold and investigate properties of amplitude. We find that the boundary state of a cylinder is different from the boundary state of a M\"{o}bius strip. Using…
We construct the T duals of certain type IIA brane configurations with one compact dimension (elliptic models) which contain orientifold planes. These configurations realize four-dimensional $\NN=2$ finite field theories. For elliptic…
We study various aspects of orientifold projections of Type IIB closed string theory on Gepner points in different dimensions. The open string sector is introduced, in the usual constructive way, in order to cancel RR charges carried by…
In this paper we consider Type I string theory compactified on a Z_7 orbifold. The model has N=1 supersymmetry, a U(4) \otimes U(4) \otimes U(4) \otimes SO(8) gauge group, and chiral matter. There are only D9-branes (for which we discuss…