The fossil Oort cloud and the dynamics beyond Neptune
Résumé
We will present here some dynamical features of the so-called fossil Oort cloud (semi major axis between 100 and 1000 AU and perihelion beyond Neptune). This region has been considered so far as totally inert, because either the planetary perturbations or the galactic tides have an extremely weak effect. However, we will show that Kozai effect can still be efficient at very high distances from the planets, and result in high amplitude oscillations of the perihelion distance on a gigayear time-scale.