Diagrammatic cancellations and the gauge dependence of QED.

This letter examines diagrammatic cancellations for Quantum Electrodynamics (QED) in the general linear gauge. These cancellations combine Feynman graphs of various topologies and provide a method to reconstruct the gauge dependence of the electron propagator from the result of a particular gauge by means of a linear Dyson–Schwinger equation. We use this method in combination with dimensional regularization to demonstrate how the 3-loop ε -expansion in the Feynman gauge determines the ε -expansions for all gauge parameter dependent terms to 4 loops. [ABSTRACT FROM AUTHOR]