1,382 research outputs found
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
Vectorlike Particles, and Yukawa Unification in F-theory inspired
We explore the low energy implications of an F-theory inspired model
whose breaking yields, in addition to the MSSM gauge symmetry, a gauge
boson associated with a symmetry broken at the TeV scale. The zero mode
spectrum of the effective low energy theory is derived from the decomposition
of the and representations of and we parametrise
their multiplicities in terms of a minimum number of flux parameters. We
perform a two-loop renormalisation group analysis of the gauge and Yukawa
couplings of the effective theory model and estimate lower bounds on the new
vectorlike particles predicted in the model. We compute the third generation
Yukawa couplings in an F-theory context assuming an point of enhancement
and express our results in terms of the local flux densities associated with
the gauge symmetry breaking. We find that their values are compatible with the
ones computed by the renormalisation group equations, and we identify points in
the parameter space of the flux densities where the Yukawa couplings
unify.Comment: 16 pages, revised version to appear in PL
Magnetic Monopoles and Free Fractionally Charged States at Accelerators and in Cosmic Rays
Unified theories of strong, weak and electromagnetic interactions which have
electric charge quantization predict the existence of topologically stable
magnetic monopoles. Intermediate scale monopoles are comparable with detection
energies of cosmic ray monopoles at IceCube and other cosmic ray experiments.
Magnetic monopoles in some models can be significantly lighter and carry two,
three or possibly even higher quanta of the Dirac magnetic charge. They could
be light enough for their effects to be detected at the LHC either directly or
indirectly. An example based on a D-brane inspired (trinification) model with the monopole carrying three quanta of Dirac
magnetic charge is presented. These theories also predict the existence of
color singlet states with fractional electric charge which may be accessible at
the LHC.Comment: 18 pages, 2 figures, minor revisions, references adde
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