Systematics of Moduli Stabilization, Inflationary Dynamics and Power Spectrum

TL;DR

This paper investigates moduli stabilization in type IIB string theory compactifications and its implications for inflation and the scalar power spectrum, highlighting the effects of non-inflaton fields on observable predictions.

Contribution

It systematically relates moduli stabilization methods to inflation analysis, demonstrating their validity and exploring observable effects of non-inflaton fields on the power spectrum.

Findings

Stability methods are valid in the large volume limit.

Non-inflaton scalar fields can affect the scalar power spectrum.

Some effects are potentially observable with current experiments.

Abstract

We study the scalar sector of type IIB superstring theory compactified on Calabi-Yau orientifolds as a place to find a mechanism of inflation in the early universe. In the large volume limit, one can stabilize the moduli in stages using perturbative method. We relate the systematics of moduli stabilization with methods to reduce the number of possible inflatons, which in turn lead to a simpler inflation analysis. Calculating the order-of-magnitude of terms in the equation of motion, we show that the methods are in fact valid. We then give the examples where these methods are used in the literature. We also show that there are effects of non-inflaton scalar fields on the scalar power spectrum. For one of the two methods, these effects can be observed with the current precision in experiments, while for the other method, the effects might never be observable.