Quintessential inflation in variable gravity model
I will discuss a quintessential inflation model, a unified description of inflation and late-time cosmic acceleration, in variable gravity frame work. Nonminimal coupling between massive neutrinos and the scalar field is considered in Einstein frame. This model can give rise to large tensor-to-scalar ratio (r > 0.1) such that the scale of inflation is around the GUT scale which are consistent with recent BICEP2 results. Relic gravity waves have a blue spectrum due to the presence of kinetic energy dominated regime after inflation. Instant preheating is implemented to restore the nucleosynthesis constraint. Lyth bound can be evaded in this model. Scalar field tracks the background in postinflationary dynamics of the Universe. After neutrinos become non-relativistic the nonminimal coupling becomes effective and plays an important roll for the scalar field to exit from the scaling behavior and dominate over the matter giving rise to late time cosmic acceleration.