Cosmological Parameter Estimation with a Joint-Likelihood Analysis of the Cosmic Microwave Background and Big Bang Nucleosynthesis
Cosmology and Nongalactic Astrophysics
2025-12-01 v2 High Energy Physics - Phenomenology
Abstract
We present the first joint-likelihood analysis of Big Bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB) data. Bayesian inference is performed on the baryon abundance and the effective number of neutrino species, , using a CMB Boltzmann solver in combination with LINX, a new flexible and efficient BBN code. We marginalize over Planck nuisance parameters and nuclear rates to find or , for three separate reaction networks. This framework enables robust testing of the Lambda Cold Dark Matter paradigm and its variants with CMB and BBN data.
Keywords
Cite
@article{arxiv.2408.14531,
title = {Cosmological Parameter Estimation with a Joint-Likelihood Analysis of the Cosmic Microwave Background and Big Bang Nucleosynthesis},
author = {Cara Giovanetti and Mariangela Lisanti and Hongwan Liu and Siddharth Mishra-Sharma and Joshua T. Ruderman},
journal= {arXiv preprint arXiv:2408.14531},
year = {2025}
}