CERN-PH-TH/2013-018 Heterotic Mini-landscape in blow-up

Abstract: Localization properties of fields in compact extra dimensions are crucial ingredients for string model building, particularly in the framework of orbifold compactifications. Realistic models often require a slight deviation from the orbifold point, that can be analyzed using field theoretic methods considering (singlet) fields with nontrivial vacuum expectation values. Some of these fields correspond to blow–up modes that represent the resolution of orbifold singularities. Improving on previous analyses we give here an explicit example of the blow–up of a model from the heterotic Mini– landscape. An exact identification of the blow–up modes at various fixed points and fixed tori with orbifold twisted fields is given. We match the massless spectra and identify the blow–up modes as non–universal axions of compactified string theory. We stress the important role of the Green–Schwarz anomaly polynomial for the description of the resolution of orbifold singularities