Improving Euler–Heisenberg–Schwinger Effective Action with Dressed Photons

Abstract

We implement a longstanding proposal by Weisskopf to apply virtual polarization corrections to the in/out external fields in the study of the Euler–Heisenberg–Schwinger effective action. Our approach requires distinguishing the electromagnetic and polarization fields based on mathematical tools developed by Białynicki-Birula, originally for the Born–Infeld action. Our solution is expressed as a differential equation where the one-loop effective action serves as input. As a first result of our approach, we recover the higher order one-cut reducible loop diagrams discovered by Gies and Karbstein.