Exoplanet Demographics: a journey through space and time

Exoplanet demographic surveys provide a unique window into planet formation and evolution. In this talk, I will showcase three distinct features in the exoplanet population and offer theoretical interpretation of the physical mechanisms that sculpt them. First, I will explore the origins of “desert dweller” planets that reside deep in the “sub-Jovian desert” (2 < Rp < 10 R_Earth, periods < 3 days), a region sparsely populated but no longer empty thanks to recent surveys. I will show that “desert dwellers” may serve as laboratories to study the fate of hot Jupiters and the interiors of giant planets in exquisite detail. I will then discuss the tidal migration histories of Neptunes in the recently identified “ridge” (periods ∼3−6 days), a feature that has been suggested to be populated via high eccentricity migration (HEM) of more distant Neptunes. I will show that coupling close-in Neptunes’ internal structures to their tidal migration histories could yield a novel constraint on the tidal dissipation mechanism at work in their interiors. Lastly, I will highlight what recent measurements extending the exoplanetary census beyond the solar neighborhood can tell us about how planet formation has evolved over cosmic time.