Natural inflation in supergravity and beyond

Abstract

Supergravity models of natural inflation and its generalizations are presented. These models are special examples of the class of supergravity models proposed in [R. Kallosh and A. Linde, J. Cosmol. Astropart. Phys. 11 (2010) 011; R. Kallosh, A. Linde, and T. Rube, Phys. Rev. D 83, 043507 (2011)], which have a shift symmetric K\"ahler potential, superpotential linear in goldstino, and stable Minkowski vacua. We present a class of supergravity models with arbitrary potentials modulated by sinusoidal oscillations, similar to the potentials associated with axion monodromy models. We show that one can implement natural inflation in supergravity even in the models of a single axion field with axion parameters $O(1)$. We also discuss the irrational axion landscape in supergravity, which describes a potential with an infinite number of stable Minkowski and metastable dS minima.