Natural Inflation and Universal Hypermultiplet

Understand

A novel framework is proposed for embedding the natural inflation into the type IIA superstrings compactified on a Calabi-Yau (CY) three-fold.

• Inflaton is identified with axion of the Universal Hypermultiplet (UH).
• The other UH scalars (including dilaton) are stabilized by the CY fluxes whose impact can be described by gauging of the abelian isometry associated with the axion, when the NS5-brane instanton contributions are suppressed.
• Then the stabilizing scalar potential is controlled by the integrable three-dimensional Toda equation, and leads to spontaneous N=2 SUSY breaking.