Related papers: Exact Standard Model Structures from Intersecting …
Intersecting D-brane models in string theory can naturally support the gauge and matter content of left-right symmetric extensions of the Standard Model with gauge symmetry SU(3)_c x SU(2)_L x SU(2)_R x U(1)_{B-L}. Considering such models…
We explore the possibility of embedding the Pati-Salam model in the context of Type I brane models. We study a generic model with U(4)_C x U(2)_L x U(2)_R gauge symmetry and matter fields compatible with a Type I brane configuration.…
Well-defined non-perturbative formulations of the physics of string theories, sometimes with D-branes present, were identified over a decade ago, from a careful study of double scaled matrix models. Following recent work which recasts some…
As a further elaboration of the proposal of Ref. [1] we address the construction of Standard-like models from configurations of stacks of orientifold planes and D-branes on an internal space with the structure ${(Gepner model)^{c=6} \times…
We perform a systematic search for globally defined MSSM-like and left-right symmetric models on D6-branes on the T6/Z(2)xZ(6)xOR orientifold with discrete torsion. Our search is exhaustive for models that are independent of the value of…
We give a complete classification of T6/[Z(2)xZ(2M)xOmegaR] orientifolds on factorisable tori and rigid D6-branes on them. The analysis includes the supersymmetry, RR tadpole cancellation and K-theory conditions and complete massless open…
We develop tools for analyzing the space of intersecting brane models. We apply these tools to a particular T^6/Z_2^2 orientifold which has been used for model building. We prove that there are a finite number of intersecting brane models…
Conventional superstring derived E$_6$ models can accommodate small neutrino masses if a discrete symmetry is imposed which forbids tree level Dirac neutrino masses but allows for radiative mass generation. Since the only possible…
We systematically study the extension of the Supersymmetric Standard Model (SSM) by an anomaly-free discrete gauge symmetry Z_N. We extend the work of Ibanez and Ross with N=2,3 to arbitrary values of N. As new fundamental symmetries, we…
Starting from an N=1 supersymmetric electric gauge theory with the gauge group SU(N_c) x SU(N_c') x SU(N_c'') with fundamentals for each gauge group, the bifundamentals, a symmetric flavor and a conjugate symmetric flavor for SU(N_c), we…
We present a general rule determining how extremal branes can interesect in a configuration with zero binding energy. The rule is derived in a model independent way and in arbitrary spacetime dimensions $D$ by solving the equations of…
Configurations of fivebranes, twobranes and fourbranes in type IIA string theory, which give (1+1) dimensional supersymmetric gauge theories in the low energy limit, are constructed. It is shown that these brane configurations are…
In this thesis we discuss some nonperturbative and noncommutative aspects of string theory. We present low-energy background field solutions corresponding to various D-branes (and their bound states) and intersecting branes in flat and…
We provide a pedagogical introduction to a recently studied class of phenomenologically interesting string models, known as Intersecting D-Brane Models. The gauge fields of the Standard-Model are localized on D-branes wrapping certain…
We perform a systematic study of the Standard Model embedding in a D-brane configuration of type I string theory at the TeV scale. We end up with an attractive model and we study several phenomenological questions, such as gauge coupling…
We construct supersymmetric Pati-Salam flux vacua in AdS from intersecting D6-branes on T^6/(Z_2 x Z_2'). The models constructed have three generations of MSSM matter plus right-handed neutrinos. Because the cycles wrapped by the D-branes…
Local supersymmetry (SUSY) provides an attractive framework for the incorporation of gravity and unification of gauge interactions within Grand Unified Theories (GUTs). Its breakdown can lead to a variety of models with softly broken SUSY…
It is known that chiral fermions naturally appear at certain intersections of branes at angles. Motivated by this fact, we propose a string scenario in which different standard model gauge interactions propagate on different (intersecting)…
We discuss infinite families of non-supersymmetric AdS$_6$ solutions in Type IIB string theory. They are siblings of supersymmetric solutions which are associated with $(p,q)$ 5-brane webs and holographically dual to 5d SCFTs engineered by…
Soft supersymmetry breaking terms were recently derived for type IIB string flux compactifications with all moduli stabilised. Depending on the choice of the discrete input parameters of the compactification such as fluxes and ranks of…