Chaotic diffusion in planetary and galactic systems

NICOLÁS MAFFIONE; PABLO CINCOTTA; JAVIER MARTÍ; CLAUDIA GIORDANO; CRISTIAN BEAUGÉ ; NICOLÁS MAFFIONE; PABLO CINCOTTA; JAVIER MARTÍ; CLAUDIA GIORDANO; CRISTIAN BEAUGÉ

Luchon

Workshop; School for advanced sciences of Luchon: Dynamics and chaos in astronomy and physics; 2016

Universite Paul Sabatier and Universite de Toulouse

In this talk we will discuss the relevance of chaotic mixing in two different scenarios. First, we investigate the dynamical structure of the (1,-3,2) Laplace resonance in the planetary system Gliese 876 by means of diffusion experiments. The results show that  there are two main regions in the surroundings of the Laplace resonance: the inner resonant region is characterized by large Lyapunov times and very slow diffusion. Thismulti-resonant configuration seems to be responsible for its long-term stability. The outer resonant region is dominated by a extremely chaotic dynamics,  exhibiting a fast diffusion. Although these results correspond to a specific planetary system, it seems reasonable that the main characteristics of any system representing similar multi-resonant configurations could share all these main features. In the second part of this talk is focused on the relevance of chaos for halo stars in the solar neighborhood. Using a very realistic potential for the DM halo (Aquarius project), and by means of diffusion numerical experiments we find that chaotic mixing, although non-negligible, is not a significant factor in erasing for instance, local signatures of accretion events at least within a physically meaningful timescale in the Solar Neighborhood.