GUTs in type IIB orientifold compactifications Original Research Article

We systematically analyse globally consistent image GUT models on intersecting D7-branes in genuine Calabi–Yau orientifolds with O3- and O7-planes. Beyond the well-known tadpole and K-theory cancellation conditions there exist a number of additional subtle but quite restrictive constraints. For the realisation of image GUTs with gauge symmetry breaking via image flux we present two classes of suitable Calabi–Yau manifolds defined via del Pezzo transitions of the elliptically fibred hypersurface image and of the Quintic image, respectively. To define an orientifold projection we classify all involutions on del Pezzo surfaces. We work out the model building prospects of these geometries and present five globally consistent string GUT models in detail, including a 3-generation image model with no exotics whatsoever. We also realise other phenomenological features such as the image Yukawa coupling and comment on the possibility of moduli stabilisation, where we find an entire new set of so-called swiss-cheese type Calabi–Yau manifolds. It is expected that both the general constrained structure and the concrete models lift to F-theory vacua on compact Calabi–Yau fourfolds.