Big bang nucleosynthesis as a probe of fundamental "constants"

TL;DR

Big Bang nucleosynthesis serves as a sensitive early universe probe for fundamental particle physics parameters, revealing how primordial element abundances depend on these constants and guiding future theoretical improvements.

Contribution

This study derives the linear dependencies of primordial abundances on key parameters, highlighting 7Li's sensitivity and informing constraints on fundamental constant variations.

Findings

7Li is highly sensitive to fundamental parameters.

Primordial abundances depend linearly on nuclear reaction rates and binding energies.

Identifies nuclear theory areas needing development for better constraints.

Abstract

Big Bang nucleosynthesis (BBN) is the earliest sensitive probe of the values of many fundamental particle physics parameters. We have found the leading linear dependences of primordial abundances on all relevant parameters of the standard BBN code, including binding energies and nuclear reaction rates. This enables us to set limits on possible variations of fundamental parameters. We find that 7Li is expected to be significantly more sensitive than other species to many fundamental parameters, a result which also holds for variations of coupling strengths in grand unified (GUT) models. Our work also indicates which areas of nuclear theory need further development if the values of ``constants'' are to be more accurately probed.