Application of a light-front coupled-cluster method to quantum electrodynamics

TL;DR

This paper applies a light-front coupled-cluster method to quantum electrodynamics, enabling both perturbative and nonperturbative calculations of the electron's properties, including the anomalous magnetic moment.

Contribution

It introduces a novel light-front coupled-cluster approach to QED, allowing for nonperturbative solutions that sum corrections to all orders in the fine-structure constant.

Findings

Perturbative solution reproduces Schwinger's result of alpha/2pi.

Nonperturbative solution sums a subset of corrections to all orders in alpha.

Method incorporates additional physics beyond perturbation theory.

Abstract

A field-theoretic formulation of the exponential-operator technique is applied to a Hamiltonian eigenvalue problem in electrodynamics, quantized in light-front coordinates. Specifically, we consider the dressed-electron state, without positron contributions but with an unlimited number of photons, and compute its anomalous magnetic moment. A simple perturbative solution immediately yields the Schwinger result of alpha/2pi. The nonperturbative solution, which requires numerical techniques, sums a subset of corrections to all orders in alpha and incorporates additional physics.