We construct global F-theory GUT models on del Pezzo surfaces in compact Calabi-Yau fourfolds realized as complete intersections of two hypersurface constraints. The intersections of the GUT brane and the flavour branes as well as the gauge flux are described by the spectral cover construction. We consider a split S[U(4)×U(1)X ] spectral cover, which allows for the phenomenologically relevant Y...

We consider 5 dimensional E6, E7, and E8 supersymmetric grand unified theories (GUTs) on an orbifold S/Z2, in which the Higgs fields arise from the 5th components of the 5D gauge fields. We introduce matter fields in 5 dimensions, then the Yukawa interactions are induced from the gauge interactions among the 5th component of gauge fields and the bulk hyper-multiplets. The adjoint and fundamenta...

We derive an appropriate definition of transpose for quaternionic matrices and give a new panoramic review of the quaternionic groups. We aim to analyse possible quaternionic groups for GUTs.

The possibility of extra large spacetime dimensions has recently received considerable attention . One of the first serious investigations of the phenomenological properties of theories with extra large dimensions was made in Ref. , where the lightness of the supersymmetry-breaking scale was related to the largeness of a string-theoretic compactification radius. More recently, in Ref., extra la...

All-loop Finite Unified Theories (FUTs) are very interesting N = 1 supersymmetric Grand Unified Theories (GUTs) which not only realise an old field theoretic dream but also have a remarkable predictive power due to the required reduction of couplings. The reduction of the dimensionless couplings in N = 1 GUTs is achieved by searching for renormalization group invariant (RGI) relations among the...

Rick A. Relyea* and Josh R. Auld Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA *Correspondence: E-mail: [email protected] Abstract Predators commonly induce phenotypic changes that make prey better at surviving predation at the cost of reduced growth. While we have a good understanding of how trait changes affect predation risk, we lack a mechanistic under...