Effective Stability Around Periodic Orbits of the Spatial RTBP

In this work we study the dynamics around an elliptic periodic orbit of Hamiltonian systems. To this end we have developped an algorithm to compute a normal form (up to a finite order) around this orbit, that gives an accurate description of the dynamics close to it. If the remainder of this normal form can be bounded, it is not difficult to produce explicit bounds of the diffusion time of trajectories starting near the periodic orbit. In order to discuss the effectivity of the method, it will be explained at the same time that it is applied to a concrete example. The one used here has been the Spatial Restricted Three Body Problem (RTBP