From Hybrid to Quadratic Inflation With High-Scale Supersymmetry
  Breaking
  Motivated by the reported discovery of inflationary gravity waves by the
BICEP2 experiment, we propose an inflationary scenario in supergravity, based
on the standard superpotential used in hybrid inflation. The new model yields a
tensor-to-scalar ratio r ~ 0.14 and scalar spectral index ns ~ 0.964,
corresponding to quadratic (chaotic) inflation. The important new ingredients
are the high-scale, (1.6-10) x 10^13 GeV, soft supersymmetry breaking mass for
the gauge singlet inflaton field and a shift symmetry imposed on the K\"ahler
potential. The end of inflation is accompanied, as in the earlier hybrid
inflation models, by the breaking of a gauge symmetry at (1.2-7.1) x 10^16 GeV,
comparable to the grand-unification scale.
