UC Irvine

Numerical and N-body simulations are used across astrophysics in problems ranging from the small-- modeling stellar winds, or planetary atmospheres-- to the large-- in simulations of large patches of cosmos or individual galaxies. Applications studied in this dissertation span this entire range of scales of the cosmos and include the exploration for alternate states of habitability on extrasolar planets, and modeling gravothermal collapse in Self-Interacting-Dark-Matter (SIDM) halos. I develop simulation codes to study planetary habitability on the edge of the runaway greenhouse and (runaway) core collapse in DM halos that galaxies reside in. A variety of common code implementations for SIDM N-body simulations is tested and numerical effects are outlined for typical usages of such codes. With these models, the Eccentric Habitable Zone (EHZ) is constrained for wide range of planetary orbits, and I present a set of equations to predict the evolution of SIDM halos under any velocity-dependent self-interaction cross section. Additionally, we explore the potential for a new planetary habitable state we termed ''Terminator Habitability" on water rich planets.