69 research outputs found
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.Comment: 37 pages. Based on Talk presented at Corfu 2011 Workshop "Fields and
Strings: Theory - Cosmology - Phenomenology. September 14 - 18, 2011".
(Prepared for the proceedings
On the Octonionic Self Duality equations of 3-brane Instantons
We study the octonionic selfduality equations for -branes in the light
cone gauge and we construct explicitly, instanton solutions for spherical and
toroidal topologies in various flat spacetime dimensions ,
extending previous results for membranes. Assuming factorization of time
we reduce the self-duality equations to integrable systems and we determine
explicitly periodic, in Euclidean time, solutions in terms of the elliptic
functions. These solutions describe 4d associative and non-associative
calibrations in dimensions. It turns out that for spherical topology
the calibration is non compact while for the toroidal topology is compact. We
discuss possible applications of our results to the problem of 3-brane topology
change and its implications for a non-perturbative definition of the 3-brane
interactions.Comment: 15 pages, 4 figure
Non-Minimal Quartic Inflation in Supersymmetric SO(10)
We describe how quartic () inflation with non-minimal
coupling to gravity is realized in realistic supersymmetric models. In
a well-motivated example the Higgs multiplets, which break
to and yield masses for the right-handed neutrinos, provide
the inflaton field . Thus, leptogenesis is a natural outcome in this
class of models. Moreover, the adjoint (45-plet) Higgs also acquires a
GUT scale value during inflation so that the monopole problem is evaded. The
scalar spectral index is in good agreement with the observations and ,
the tensor to scalar ratio, is predicted for realistic values of GUT parameters
to be of order .Comment: 10 pages, 1 figur
- …