Investigation of the electromagnetically induced transparency in era of cosmological hydrogen recombination

TL;DR

This paper explores how electromagnetically induced transparency (EIT) in hydrogen atoms during the universe's recombination era affects cosmic microwave background formation, suggesting updates to astrophysical models.

Contribution

It introduces the consideration of EIT phenomena in cosmological hydrogen recombination, revealing small but significant corrections to the Sobolev escape probability.

Findings

EIT occurs during hydrogen recombination.

Additional terms to optical depth are about 1%.

Implications for cosmic microwave background modeling.

Abstract

Investigation of the cosmic microwave background formation processes is one of the most actual problem at present time. In this paper we analyze the response of the hydrogen atom to the external photon fields. Field characteristics are defined via conditions corresponding to the recombination era of universe. Approximation of three-level atom is used to describe the "atom - fields" interaction. It is found that the phenomena of the electromagnetically induced transparancy takes place in this case. Consideration of EIT phenomena makes it necessary to update astrophysical description of the processes of the cosmic microwave background formation and, in particular, Sobolev escape probability. Additional terms to the optical depth in definition of Sobolev escape probability on the level about 1% are found.