Abstract

Extrasolar planets exhibit a large variety of orbital properties, from packed, coplanar, multiple systems on circular orbits, to eccentric and misaligned hot Jupiters. Such variety reflects the diversity of dynamical interactions that can take place within planetary systems, and which start soon after their birth in a protoplanetary disc. I will present different aspect of planet-disc interactions that can cause large variations of eccentricity and inclination in the planetary orbits. First, we study the interaction between a planet on an inclined orbit and a disc, and show that realignment of the planetary orbit strongly depends on the mass of the planet. Furthermore, Kozai cycles raised by the disc’s gravitational potential can strongly excite the planet’s eccentricity and inclination. Secondly, we study the resonant migration of two planets in a disc. We explore, analytically and numerically, the criterion for the onset of an inclination-type resonance. We show that it depends mainly on the ratio between the eccentricity damping timescale and the migration timescale.