Inflationary cosmology in the central region of String/M-theory moduli space

TL;DR

This paper proposes that the central region of string/M-theory moduli space can naturally support slow-roll inflation with correct CMB anisotropy predictions, overcoming previous theoretical obstacles.

Contribution

It demonstrates that non-perturbative potentials in the central moduli space can enable viable slow-roll inflation with realistic CMB predictions.

Findings

Non-perturbative potentials support slow-roll inflation.

Predicted scalar spectrum is red, tensor perturbations are negligible.

Inflationary model consistent with string/M-theory framework.

Abstract

The "central" region of moduli space of M- and string theories is where the string coupling is about unity and the volume of compact dimensions is about the string volume. Here we argue that in this region the non-perturbative potential which is suggested by membrane instanton effects has the correct scaling and shape to allow for enough slow-roll inflation, and to produce the correct amplitude of CMB anisotropies. Thus, the well known theoretical obstacles for achieving viable slow-roll inflation in the framework of perturbative string theory are overcome. Limited knowledge of some generic properties of the induced potential is sufficient to determine the simplest type of consistent inflationary model and its predictions about the spectrum of cosmic microwave background anisotropies: a red spectrum of scalar perturbations, and negligible amount of tensor perturbations.