Modified natural inflation: A small single field model with a large tensor to scalar ratio

Understand

In this paper we explored in detail a phenomenological model of modified single field natural inflation in light of recent cosmological experiments, BICEP2.

• Our main goal is to construct an inflationary model which not only predicts the important cosmological quantities such as $(n_s, r)$ compatible with experimental observation, but also is consistent with the low energy effective theory framework.
• Therefore, all the fundamental scale apart from $M_p$ and quantities of our interest should be within the sub-Planckian region.
• In order to achieve our goal we modify the usual single field natural inflationary model by a specific form of higher derivative kinetic term called kinetic gravity braiding (KGB).