Modular Cosmology
T. Banks, M. Berkooz, G. Moore, S. H. Shenker, P. J. Steinhardt
TL;DR
It is shown that string theory has two generic types of domain walls which could be the seeds for inflation, and it is argued that modular physics provides a very robust model of inflation.
Abstract
An exploratory study of the cosmology of moduli in string theory. Moduli are argued to be natural inflaton fields and lead to a robust inflationary cosmology in which inflation takes place at the top of domain walls. The amplitude of microwave background fluctuations constrains the dynamics responsible for inflation to take place at a higher scale than supersymmetry breaking. Models explaining this difference in scales and also preventing the dilaton from running to infinity are proposed. The problem of dilaton domination of the energy density of the universe is not resolved.