Baryogenesis from a Modulus Dominated Universe

TL;DR

This paper explores how baryon asymmetry can be regenerated in a universe dominated by a heavy modulus field, linking the small asymmetry to fundamental scale hierarchies in string/M-theory.

Contribution

It proposes a novel mechanism for baryogenesis via modulus decay, connecting the hierarchy problem to the generation of matter-antimatter asymmetry.

Findings

Modulus decay at MeV temperatures can produce the observed baryon asymmetry.

The smallness of the asymmetry is related to the hierarchy between the Planck and Fermi scales.

The mechanism provides a consistent baryogenesis scenario within string/M-theory frameworks.

Abstract

String/ M-theory compactifications predict the existence of a modulus field with a mass of 100-10000 TeV. Its decay at MeV-temperatures generates large amounts of entropy and washes out any previously produced baryon asymmetry. We describe how the baryon asymmetry can be (re)generated by the modulus decay. The mechanism relates the smallness of the asymmetry to the hierarchy between the Planck- and the Fermi-scale.