Numerical cancellation of photon quadratic divergence in the study of the Schwinger-Dyson equations in Strong Coupling QED

TL;DR

This paper investigates the numerical treatment of quadratic divergences in the photon renormalization function within strong coupling QED, revealing that previous sharp features were artifacts of divergence removal methods.

Contribution

It proposes a new approach to avoid artifacts caused by divergence subtraction in numerical solutions of Schwinger-Dyson equations in strong coupling QED.

Findings

The sharp decrease in the photon renormalization function is an artifact.

A method to prevent divergence subtraction artifacts in numerical studies.

Improved understanding of photon behavior in strong coupling QED.

Abstract

The behaviour of the photon renormalization function in strong coupling QED has been recently studied by Kondo, Mino and Nakatani. We find that the sharp decrease in its behaviour at intermediate photon momenta is an artefact of the method used to remove the quadratic divergence in the vacuum polarization. We discuss how this can be avoided in numerical studies of the Schwinger-Dyson equations.