On Cosmological Low Entropy After the Big Bang: Universal Expansion and Nucleosynthesis
Abstract
We investigate the sensitivity of a universe's nuclear entropy after Big Bang nucleosynthesis (BBN) to variations in both the baryon-to-photon ratio and the temporal evolution of cosmological expansion. Specifically, we construct counterfactual cosmologies to quantify the degree by which these two parameters must vary from those in our Universe before we observe a substantial change in the degree of fusion, and thus nuclear entropy, during BBN. We find that, while the post-BBN nuclear entropy is indeed linked to baryogenesis and the Universe's expansion history, the requirement of leftover light elements does not place strong constraints on the properties of these two cosmological processes.
Keywords
Cite
@article{arxiv.2302.03988,
title = {On Cosmological Low Entropy After the Big Bang: Universal Expansion and Nucleosynthesis},
author = {Charlie F. Sharpe and Luke A. Barnes and Geraint F. Lewis},
journal= {arXiv preprint arXiv:2302.03988},
year = {2023}
}
Comments
15 pages, 5 figures. It has been accepted for publishing but has not yet appeared. The journal is General Relativity and Gravitation