Graceful exit from inflation to radiation era with rapidly decreasing   agegraphic potentials
  We present a class of models where both the primordial inflation and the late times de Sitter phase are driven by simple phenomenological agegraphic potentials. In this context, a possible new scenario for a smooth exit from inflation to the radiation era is discussed by resorting the kination (stiff) era but without the inefficient radiation production mechanism of these models. This is done by considering rapidly decreasing expressions for $V(t)$ soon after inflation. We show that the parameters of our models can reproduce the scalar spectral parameter $n_s$ predicted by Planck data in particular for models with concave potentials. Finally, according to the recent BICEP2 data, all our models allow a huge amount of primordial gravitational waves. 
Stefano Viaggiu, Marco Montuori
astro-ph.CO gr-qc hep-th