Hot primordial regions with anomalous hydrogenless chemical composition

TL;DR

This paper investigates primordial hot regions formed by density inhomogeneities, showing they can develop high metallicity and predominantly produce helium-4, impacting early universe chemical evolution.

Contribution

It introduces a model of primordial hot regions with anomalous composition and analyzes their nucleosynthesis, highlighting their potential to alter early universe metallicity.

Findings

Regions acquire high metallicity surviving to present

All baryons tend to form helium-4 in these regions

Estimated abundances of deuterium and helium isotopes

Abstract

We study primordial nucleosynthesis in hypothetical hot regions that could be formed by the primordial density inhomogeneities. It is shown that the regions survived up to the present times acquire an abnormally high metallicity. This conclusion holds in wide range of initial parameters of such regions. We considered the thermonuclear reaction rates and estimated abundances of deuterium and helium-3 and -4 inside these areas. It has been established that all baryons tend to form helium-4, which is the thermonuclear link in the chain of formation of heavier elements.