Primordial Nucleosynthesis as a test of variable rest masses 5-dimensional cosmology

TL;DR

This paper investigates how variations in nucleon rest masses could affect primordial helium production, providing bounds on mass differences and testing a specific theory of gravitation against observational data.

Contribution

It introduces a method to constrain variations in nucleon masses during nucleosynthesis and evaluates Wesson's theory, ruling it out based on observational bounds.

Findings

Upper bound on nucleon mass difference variation: 0.129 MeV

Wesson's theory of gravitation is incompatible with observational data

Primordial helium production is sensitive to nucleon mass differences

Abstract

The deviation of primordial Helium production due to a variation on the difference between the rest masses of the nucleons is presented. It is found an upper bound $\delta (M_{_n} - M_{_p}) \alt 0.129$ MeV, between the present and nucleosynthesis epochs. This bound is used to analyze Wesson's theory of gravitation; as a result, it is ruled out by observation.