Hydrogen recombination in the early Universe in the presence of a magnetic field

TL;DR

This paper investigates how magnetic fields influence hydrogen recombination in the early Universe, deriving an equation for the recombination temperature and identifying a critical magnetic field affecting the phase of atomic hydrogen.

Contribution

It introduces a new equation for recombination temperature considering magnetic fields and analyzes the effects of weak and strong magnetic fields on hydrogen recombination.

Findings

Existence of a critical magnetic field above which hydrogen remains atomic at all temperatures

The relative shift in recombination temperature due to magnetic fields is small

Recombination behavior varies significantly between weak and strong magnetic field regimes

Abstract

Hydrogen recombination in the early Universe in the presence of a magnetic field is studied. An equation for the temperature of recombination in the presence of a magnetic field is derived. Limiting cases of weak and strong fields are considered. It is demonstrated that there exists a critical magnetic field, above which the system stays in the phase of atomic hydrogen for all temperatures. The relative shift of the temperature of recombination in the presence of a magnetic field is estimated and it is demonstrated that this shift is small.