Chaotic inflation and unitarity problem

Understand

We consider a general chaotic inflation model with non-canonical kinetic term, resulting in attractor solutions for the inflation of quadratic or other monomial type.

• In particular, the form of the kinetic term and the potential is fixed due to the requirement that the inflation model is a quadratic form in the large field values of the inflaton.
• We show that a large coupling in the non-canonical kinetic term allows for the slow-roll inflation with sub-Planckian field values of the inflaton and the successful predictions of the quadratic or other monomial type chaotic inflation in light of BICEP2 results are maintained in our model.
• We find that due to the large rescaling of the inflaton field in the vacuum, there is no unitarity problem below the Planck scale.