Towards natural inflation from weakly coupled heterotic string theory

TL;DR

This paper proposes a model of natural inflation derived from heterotic string theory on a Swiss-Cheese Calabi-Yau manifold, where multiple U(1) fluxes stabilize moduli and produce a trans-Planckian axion decay constant compatible with observational data.

Contribution

It introduces a novel string-theoretic realization of natural inflation with stabilized moduli and a trans-Planckian axion decay constant from one-loop corrections.

Findings

Achieves a trans-Planckian axion decay constant consistent with observational data.

Stabilizes moduli using the structure of Swiss-Cheese Calabi-Yau manifolds.

Provides a string-theoretic framework for natural inflation.

Abstract

We propose the natural inflation from the heterotic string theory on "Swiss-Cheese" Calabi-Yau manifold with multiple $U(1)$ magnetic fluxes. Such multiple $U(1)$ magnetic fluxes stabilize the same number of the linear combination of the universal axion and K\"ahler axions and one of the K\"ahler axions is identified as the inflaton. This axion decay constant can be determined by the size of one-loop corrections to the gauge kinetic function of the hidden gauge groups, which leads effectively to the trans-Planckian axion decay constant consistent with the WMAP, Planck and/or BICEP2 data. During the inflation, the real parts of the moduli are also stabilized by employing the nature of the "Swiss-Cheese" Calabi-Yau manifold.