The Baryon-Dark Matter Ratio Via Moduli Decay After Affleck-Dine Baryogenesis

TL;DR

This paper explores how moduli decay after Affleck-Dine baryogenesis can naturally explain the observed ratio of baryonic matter to dark matter, addressing the cosmic coincidence problem in a string-inspired supersymmetric framework.

Contribution

It demonstrates a novel connection between moduli decay, baryon asymmetry, and dark matter abundance, providing a unified solution to the cosmic coincidence problem.

Findings

Moduli decay can produce the correct dark matter relic density.

The mechanism can resolve the over-production of baryon asymmetry.

A natural link between baryon and dark matter densities is established.

Abstract

Low-scale supersymmetry breaking in string motivated theories implies the presence of O(100) TeV scale moduli, which generically lead to a significant modification of the history of the universe prior to Big Bang Nucleosynthesis. Such an approach implies a non-thermal origin for dark matter resulting from scalar decay, where the lightest supersymmetric particle can account for the observed dark matter relic density. We study the further effect of the decay on the baryon asymmetry of the universe, and find that this can satisfactorily address the problem of the over-production of the baryon asymmetry by the Affleck-Dine mechanism in the MSSM. Remarkably, there is a natural connection between the baryon and dark matter abundances today, which leads to a solution of the `Cosmic Coincidence Problem'.