|Abstract : ||Observations suggest that adjacent exoplanets, like peas in a pod, tend to be of similar size/mass and also have similar spacing (Weiss et al. 2018, Millholland et. al. 2017). Numerical simulations of planet formation and transit detections are able to reproduce these trends in good agreement with observations (Mishra et al. 2021).
To gain a deeper understanding, I propose a system level framework for characterizing the architecture of individual planetary systems (Mishra et al, in prep.). This framework allows us to: quantify, compare, and investigate the architecture of a single planetary system. This new framework naturally partitions the space of system architectures into four classes: Similar, Ordered, Anti-Ordered, and Mixed. It unveils new correlations between system architecture and internal composition of planets in this system. New questions emerge: What is the most common architecture type in the galaxy? A first glimpse into the occurrence rate of planetary system architectures is presented.
Focusing on the formation pathways, the role of nature (initial conditions from star/disk environment) versus nurture (physical processes occurring during planet formation) for producing these architecture types is studied. While initial conditions play a major role in producing similar type architectures, dynamical interactions are imperative for producing the other architecture types. This work predicts strong testable links between initial conditions and the final architecture. Although observations are few, they are in agreement with the predictions from this work. Observations from PLATO may provide enough data to statistically refute/confirm these predictions.|