Higher Derivative Corrections to String Inflation

TL;DR

This paper estimates the impact of higher derivative corrections on string inflation models derived from IIB supergravity, showing they generally do not alter key cosmological predictions and identifying geometries suitable for various inflation scenarios.

Contribution

It provides a systematic analysis of higher derivative corrections in string inflation models using large database scans, identifying geometries where corrections are negligible or manageable.

Findings

Several geometries suitable for different inflation models.

Higher derivative corrections typically do not spoil inflation predictions.

Classification of divisor topologies with vanishing corrections.

Abstract

We quantitatively estimate the leading higher derivative corrections to ${\mathcal{N}}=1$ supergravity derived from IIB string compactifications and study how they may affect moduli stabilisation and LVS inflation models. Using the Kreuzer-Skarke database of 4D reflexive polytopes and their triangulated Calabi-Yau database, we present scanning results for a set of divisor topologies corresponding to threefolds with $1 \leq h^{1,1} \leq 5$. In particular, we find several geometries suitable to realise blow-up inflation, fibre inflation and poly-instantons inflation, together with a classification of the divisors topologies for which the leading higher derivative corrections to the inflationary potential vanish. In all other cases, we instead estimate numerically how these corrections modify the inflationary dynamics, finding that that they do not destroy the predictions for the main cosmological observables.