# Poly-instanton axion inflation

## TL;DR

This paper explores a string theory-based axion inflation model derived from poly-instanton effects, demonstrating its potential to produce a flat inflationary potential suitable for cosmic inflation and analyzing its cosmological predictions.

## Contribution

It introduces a novel axion inflation model based on poly-instanton effects in type II superstring theories, with detailed numerical analysis of inflationary dynamics and observables.

## Key findings

- Potential can support slow-roll inflation due to exponential suppression
- Numerical results show compatibility with observed spectral index
- Model predicts specific values for cosmological parameters

## Abstract

We investigate the axion inflation model derived by poly-instanton effects in type II superstring theories. Poly-instanton effects are instanton effects corrected by another instanton and it can generate the modulus-axion potential with the double exponential function. Although the axion has a period of small value, this potential can have a flat region because its derivatives are exponentially suppressed by non-perturbative effects. From the view point of the cosmic inflation, such potential is interesting. In this paper, we numerically study the possibilities for realizing the cosmic inflation. We also study their spectral index and other cosmological observables, numerically.