Aspects of F-Theory GUTs
  The basic tools for model building in F-theory are reviewed and applied to the construction of SU(5) models. The flux mechanism for gauge symmetry breaking and doublet triplet splitting is analysed. A short account for the gauge coupling unification and the role of flux and Kaluza-Klein thresholds is also given. 
George K. Leontaris
hep-th hep-ph