Explaining the Radius Cliff in Exoplanet Occurrences using Advanced Sub-Neptune Models

The radius cliff in the radius-occurrence diagram of close-in exoplanets remains challenging to model. Therefore, we propose to construct improved equilibrium chemistry models of sub-Neptunes that account for hydrogen dissolution in the magma mantle. By including new laboratory experimental data and integrating these models with mass loss processes, our goal is to reproduce the observed radius cliff and provide a more accurate understanding of its origin. If this project shows that the origin of the radius cliff is due to hydrogen dissolution, it will fundamentally change the understanding of planet formation.