M-Theory Moduli Space and Cosmology

TL;DR

This paper explores the moduli space of M-theory and string theories to identify regions that could support realistic cosmologies with inflation and stabilized moduli, emphasizing the importance of the non-perturbative central region.

Contribution

It introduces a simplified duality framework that truncates the moduli space, highlighting the non-perturbative central region as the most promising for viable cosmological models.

Findings

Outer perturbative regions are not viable for realistic cosmology.

Duality relations simplify the moduli space analysis.

Central non-perturbative region is most promising for cosmology.

Abstract

We conduct a systematic search for a viable string/M-theory cosmology, focusing on cosmologies that include an era of slow-roll inflation, after which the moduli are stabilized and the Universe is in a state with an acceptably small cosmological constant. We observe that the duality relations between different cosmological backgrounds of string/M-theory moduli space are greatly simplified, and that this simplification leads to a truncated moduli space within which possible cosmological solutions lie. We review some known challenges to four dimensional models in the "outer", perturbative, region of moduli space, and use duality relations to extend them to models of all of the (compactified) perturbative string theories and 11D supergravity, including brane world models. We conclude that cosmologies restricted to the outer region are not viable, and that the most likely region of moduli space in which to find realistic cosmology is the "central", non-perturbative region, with coupling and compact volume both of order unity, in string units.