Finite temperature wave-function renormalization: A comparative analysis

We compare two competing theories regarding finite temperature wave-function corrections for the process H-->e(+)e(-) and for n+v-->p+e(-) and related processes of interest for primordial nucleosynthesis. Although the two methods are distinct (as shown in H-->e(+)e(-)) they yield the same finite temperature correction for all n-->p and p-->n processes. Both methods yield an increase in the He/H ratio of 0.01% due to finite temperature renormalization rather than a decrease of 0.16% as previously predicted.