Planetary System Evolution: Giant Planet Eccentricity & Nonconservative N-body Dynamics

David Tsang, University of Maryland

I will discuss two topics relevant to the evolution of young planetary systems: the eccentricity evolution of giant planets while they are still embedded in their natal disks, and a new approach to N-body dynamics that can be used to study a system during later times. In the first part of the talk I will show how entropy gradients within the disk can modify the eccentricity distribution of giant exoplanets, which may bear the imprint of the disk structure as a function of metallicity. In the second part, I will briefly review the principles behind symplectic integrators for conservative N-body dynamics. Utilizing a newly developed nonconservative action principle, I will demonstrate how this allows for the formulation of nonconservative (“Slimplectic”) variational integrators: numerical integrators with the long-term accuracy properties of symplectic integrators but for systems that have dissipation or other nonconservative physics (e.g. tides, radiation reaction, drag), allowing for long-term numerical study of planetary systems where dissipative interactions can play an important dynamical role.