Natural Inflation in Supergravity and Beyond

TL;DR

This paper develops supergravity models for natural inflation, including sinusoidally modulated potentials and an irrational axion landscape, demonstrating the feasibility of inflation with single axion fields and complex potential structures.

Contribution

It introduces supergravity models with sinusoidal modulations and an infinite landscape of minima, expanding the theoretical framework for natural inflation.

Findings

Natural inflation achievable with single axion in supergravity.

Models include sinusoidal modulations similar to axion monodromy.

Infinite stable and metastable minima in the potential landscape.

Abstract

Supergravity models of natural inflation and its generalizations are presented. These models are special examples of the class of supergravity models proposed in arXiv:1008.3375 and arXiv:1011.5945, 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 infinite number of stable Minkowski and metastable dS minima.