Cosmological stabilization of moduli with steep potentials

TL;DR

This paper proposes a cosmological mechanism where additional sources and cosmic friction help stabilize steep moduli potentials in string theory, overcoming the overshoot problem by dissipating excess kinetic energy.

Contribution

It introduces a novel stabilization scenario leveraging cosmic friction and small additional sources to address the steep potential overshoot issue in string moduli.

Findings

Kinetic energy of moduli red-shifts faster than other sources.

Additional small sources can dominate and facilitate stabilization.

Analytic and numerical evidence supports the proposed mechanism.

Abstract

A scenario which overcomes the well-known cosmological overshoot problem associated with stabilizing moduli with steep potentials in string theory is proposed. Our proposal relies on the fact that moduli potentials are very steep and that generically their kinetic energy quickly becomes dominant. However, moduli kinetic energy red-shifts faster than other sources when the universe expands. So, if any additional sources are present, even in very small amounts, they will inevitably become dominant. We show that in this case cosmic friction allows the dissipation of the large amount of moduli kinetic energy that is required for the field to be able to find an extremely shallow minimum. We present the idea using analytic methods and verify with some numerical examples.