The role of metallicity in forming super-Earths and sub-Neptunes

Core-accretion leads us to believe that more solid material makes larger super-Earths and sub-Neptunes more frequently. However, the strength of both of these dependencies on metallicity fade in up-to-date samples of planet candidates. The implications for planet formation are twofold. First, there is likely an unknown process affecting the final core masses of super-Earths and sub-Neptunes. Second, the failure in lower metallicity systems may be due to other disruptions (such as close binaries). This raises the question of whether super-Earths and sub-Neptunes more reliant on core-accretion, or external processes? In this talk I will describe a novel technique to quantify these weak dependencies and explore the consequences of a weak metallicity reliance.