Freeze-in baryogenesis and early matter domination

TL;DR

This paper investigates how early matter domination influences ultraviolet freeze-in baryogenesis, revealing that it permits lower reheating temperatures and links inflationary observables to baryogenesis models.

Contribution

It demonstrates that early matter domination significantly alters freeze-in baryogenesis predictions and connects inflationary data with baryogenesis parameters.

Findings

Lower reheating temperatures are achievable under early matter domination.

Inflationary observables can constrain baryogenesis model parameters.

Early matter domination impacts the viability of ultraviolet freeze-in scenarios.

Abstract

The freeze-in mechanism has been shown to allow the simultaneous generation of cosmic dark matter and a viable matter-antimatter asymmetry in the universe. When the underlying interactions are described by higher-dimensional, non-renormalizable operators, the relevant freeze-in processes take place close to the highest considered cosmic temperatures. In this paper we study how the presence of a fluid that temporarily dominates the energy content of the early universe affects the predictions of this ``Ultraviolet Freeze-In Baryogenesis'' scenario. We find that this additional cosmic component has a significant impact on the predictions of concrete microscopic models, allowing for reheating temperatures which are much lower than those required in the simplest cosmological scenario. Moreover, we show that inflationary observables can constrain the parameter space of such models, once the latter are examined in conjunction with concrete models of inflation.