Two-photon approximation in the theory of the electron recombination in hydrogen

TL;DR

This paper develops a rigorous quantum electrodynamics (QED) framework for modeling two-photon decay processes in hydrogen, aiding understanding of atomic recombination and early universe hydrogen history.

Contribution

It introduces a formal two-photon approximation within QED for hydrogen, encompassing cascades and transitions, enhancing the theoretical description of atomic recombination.

Findings

Formulation of a two-photon approximation in QED for hydrogen

Potential application to early Universe hydrogen recombination

Provides a basis for more accurate atomic decay modeling

Abstract

A rigorous QED theory of the multiphoton decay of excited states in hydrogen atom is presented. The "two-photon" approximation is formulated which is limited by the one-photon and two-photon transitions including cascades transitions with two-photon links. This may be helpful for the strict description of the recombination process in hydrogen atom and, in principle, for the history of the hydrogen recombination in the early Universe.