The solar, exoplanet and cosmological lithium problems

TL;DR

This paper reviews three lithium-related problems in solar, stellar, and cosmological contexts, explaining them through non-standard stellar mixing processes, and clarifies misconceptions about lithium abundance discrepancies.

Contribution

It provides a unified explanation for the lithium problems across different astrophysical environments using non-standard stellar mixing.

Findings

Non-standard mixing explains the solar Li problem.

Stellar mixing accounts for Li differences in planet-hosting stars.

Cosmological Li discrepancy is linked to stellar processes, not primordial abundance.

Abstract

We review three Li problems. First, the Li problem in the Sun, for which some previous studies have argued that it may be Li-poor compared to other Suns. Second, we discuss the Li problem in planet hosting stars, which are claimed to be Li-poor when compared to field stars. Third, we discuss the cosmological Li problem, i.e. the discrepancy between the Li abundance in metal-poor stars (Spite plateau stars) and the predictions from standard Big Bang Nucleosynthesis. In all three cases we find that the "problems" are naturally explained by non-standard mixing in stars.