Generalized LKF transformations for $N$-point fermion correlators in QED

TL;DR

This paper derives a generalized transformation in QED that describes how fermion correlators in position space depend on the gauge parameter, revealing a multiplicative exponential factor that captures non-perturbative gauge dependence.

Contribution

It introduces a generalized form of LKFt within the worldline approach, extending understanding of gauge dependence in non-perturbative QED correlators.

Findings

Derived a non-perturbative gauge transformation for fermion correlators.

Showed gauge dependence can be absorbed into an exponential factor.

Extended LKFt to a broader class of correlators.

Abstract

Within the worldline approach to quantum electrodynamics (QED), a change of the photon's covariant gauge parameter $\xi$ is investigated to analyse the non-perturbative gauge dependence of the configuration space fermion correlation functions, deriving a generalization of the Landau-Kalatnikov-Fradkin transformations (LKFt). These transformations reveal how the non-perturbative gauge dependence of position space amplitudes can be absorbed into a multiplicative exponential factor.