The Fermionic Propagator in an Intense Background

TL;DR

This paper derives a compact all-orders expression for the fermion propagator in a laser background, incorporating matrix wave function renormalisation and mass shift, with perturbative verification.

Contribution

It presents a novel, compact formulation of the fermion propagator in intense backgrounds, including matrix-valued corrections and perturbative validation.

Findings

All-orders fermion propagator expressed as sum of sideband poles.

Matrix wave function renormalisation and mass shift included.

Perturbative checks confirm the results.

Abstract

New results for the fermion propagator in a laser background are presented. We show that the all orders electron propagator can be written in a compact and appealing form as a sum of sideband poles with a matrix wave function renormalisation and a matrix valued mass shift. This last result is essential in the fermionic theory if we are to maintain that both the mass and its square pick up a correction only at order e^2. A perturbative verification of our results is carried out.