Multi-Natural Inflation in Supergravity

Understand

We show that the recently proposed multi-natural inflation can be realized within the framework of 4D ${\cal N}=1$ supergravity.

• The inflaton potential mainly consists of two sinusoidal potentials that are comparable in size, but have different periodicity with a possible non-zero relative phase.
• For a sub-Planckian decay constant, the multi-natural inflation model is reduced to axion hilltop inflation.
• We show that, taking into account the effect of the relative phase, the spectral index can be increased to give a better fit to the Planck results, with respect to the hilltop quartic inflation.