Hyperbolic Inflation in the Light of Planck 2015 data
  Rubano and Barrow have discussed the emergence of a dark energy, with
late-time cosmic acceleration arising from a self-interacting homogeneous
scalar field with a potential of hyperbolic power type. Here, we study the
evolution of this scalar field potential back in the inflationary era. Using
the hyperbolic power potential in the framework of inflation, we find that the
main slow-roll parameters, like the scalar spectral index, the running of the
spectral index and the tensor-to-scalar fluctuation ratio can be computed
analytically. Finally, in order to test the viability of this hyperbolic scalar
field model at the early stages of the Universe, we compare the predictions of
that model against the latest observational data, namely Planck 2015.
