Scattering in Time-Dependent Basis Light-Front Quantization

TL;DR

This paper presents a novel nonperturbative numerical method using light-front quantization to study time-dependent quantum field theory problems, demonstrated through non-linear Compton scattering in QED with strong background fields.

Contribution

It introduces a first-principles, nonperturbative approach for time-dependent quantum field problems in light-front quantization, applied to strong-field QED processes.

Findings

Validated against perturbation theory for weak fields

Revealed nonperturbative effects in strong background fields

Tracked quantum state evolution over time

Abstract

We introduce a nonperturbative, first principles numerical approach for solving time-dependent problems in quantum field theory, using light-front quantization. As a first application we consider QED in a strong background field, and the process of non-linear Compton scattering in which an electron is excited by the background and emits a photon. We track the evolution of the quantum state as a function of time. Observables, such as the invariant mass of the electron-photon pair, are first checked against results from perturbation theory, for suitable parameters. We then proceed to a test case in the strong background field regime and discuss the various nonperturbative effects revealed by the approach.