ON THE STOCHASTICITY OF THE ASTEROID BELT

The study of the stochasticity of the asteroid belt requires the analy sis of a large number of orbits. We detect the dynamical character of a set of 5 400 asteroids using the Fast Lyapunov Indicator, a method o f analysis closely related to the computation of the Lyapunov Characte ristic Exponents, but cheaper in computational time. For both regular and chaotic orbits we try to associate the motion to the underlying re sonances network. For it we consider different methods of classificati on of rational numbers proposed by number theory, and we choose the on e which seems to be strictly related to the dynamical behaviour of a s ystem.