Nonlinear Compton scattering in time-dependent electric fields: LCFA and beyond

TL;DR

This paper investigates the validity and limitations of the locally constant crossed field approximation (LCFA) for photon emission in strong, time-dependent electric fields, extending understanding beyond the well-studied plane wave case.

Contribution

The authors develop a method to calculate photon emission probabilities in generic time-dependent electric fields and determine the applicability and corrections to LCFA in this context.

Findings

Established the range of applicability of LCFA in time-dependent electric fields.

Derived corrections to LCFA for photon emission probabilities.

Provided a framework for analyzing strong field QED effects beyond plane wave models.

Abstract

Locally constant crossed field approximation (LCFA) is a powerful tool for theoretical and numerical studies of various strong field quantum electrodynamical effects. We explore this approximation in detail for photon emission by a spinless particle in a strong time-dependent electric field. This kind of electromagnetic fields is of particular interest, because, in contrast to the comprehensively studied case of a plane wave, they are not crossed. We develop an approach for calculating photon emission probability in a generic time-dependent electric field, establish the range of applicability of LCFA, and calculate the corrections to it.