Relativistic corrections to transition frequencies of Fe I and search for variation of the fine structure constant

TL;DR

This paper calculates relativistic energy shifts in Fe I to aid in detecting potential variations of the fine structure constant over space and time, highlighting Fe's suitability for such studies.

Contribution

It provides the largest relativistic energy shift values for Fe I, improving the accuracy of searches for variations in the fine structure constant.

Findings

Largest relativistic energy shifts for Fe I to date

Fe is a promising candidate for fine structure constant variation studies

Results enhance the analysis of quasar absorption spectra

Abstract

Relativistic energy shifts of the low energy levels of Fe have been calculated using the Dirac-Hartree-Fock and configuration interaction techniques. The results are to be used in the search for the space-time variation of the fine structure constant in quasar absorption spectra. The values of the shifts are the largest among those used in the analysis so far. This makes Fe a good candidate for the inclusion into the analysis.