QED Near the Decoupling Temperature

TL;DR

This paper investigates the behavior of QED parameters near the decoupling temperature, showing that perturbation theory remains valid below this temperature and analyzing the temperature dependence of electron selfmass and electromagnetic properties.

Contribution

It provides a detailed analysis of the temperature-dependent electron selfmass near the decoupling temperature, highlighting differences in behavior at T=m and their implications.

Findings

Electron selfmass at T=m has two different values depending on approach.

Thermal contribution of electron selfmass at T=m is 1/3 of low T and 1/2 of high T values.

Contributions to QED parameters are negligible near the decoupling temperature.

Abstract

We study the effective parameters of QED near the decoupling temperature and show that the QED perturbation theory works perfectly fine at temperatures, below the decoupling temperature. Temperature dependent selfmass of electron, at T=m gives two different values, if approached to the same overlapping point. It ia shown that at $T=m$, change in thermal contribution of the electron selfmass is 1/3 of the low temperature value and 1/2 of the high temperature value. The difference of behavior measures the electron background contributions at T=m. These electrons are emitted through beta decay. This rise in mass affects the QED parameters and change the electromagnetic properties of the medium with temperature also. However, these contributions are ignorable near the decoupling temperature.