BSM

Abstract

We give a detailed account of our search for Calabi-Yau three-folds with two toric del Pezzo divisors of the same kind and an orientifold involution which maps them into each other. We will consider hypersurface Calabi-Yaus in toric four-folds with $h^{1,1}$ up to five and comment on the relevance of these geometries in string phenomenology.