Cosmology from Moduli Dynamics

TL;DR

This paper explores how fluxes in supergravity and M-theory stabilize shape moduli of extra dimensions, leading to late-time shape freezing and radion-driven cosmology, with potential implications for inflation.

Contribution

It analyzes moduli dynamics with fluxes, revealing stabilization mechanisms and diverse cosmological scenarios, including inflation, in supergravity/M-theory frameworks.

Findings

Fluxes stabilize shape moduli at late times.

Radion acts as a quintessence field.

Possible inflationary phases depending on initial conditions.

Abstract

We investigate moduli field dynamics in supergravity/M-theory like set ups where we turn on fluxes along some or all of the extra dimensions. As has been argued in the context of string theory, we observe that the fluxes tend to stabilize the squashing (or shape) modes. Generically we find that at late times the shape is frozen while the radion evolves as a quintessence field. At earlier times we have a phase of radiation domination where both the volume and the shape moduli are slowly evolving. However, depending on the initial conditions and the parameters of the theory, like the value of the fluxes, curvature of the internal manifold and so on, the dynamics of the internal manifold can be richer with interesting cosmological consequences, including inflation.