The Invariance of Poincaré's Generating Function for Canonical Transformations.
The -centre problem of celestial mechanics for large energies
We consider the classical three-dimensional motion in a potential which is the sum of attracting or repelling Coulombic potentials. Assuming a non-collinear configuration of the centres, we find a universal behaviour for all energies above a positive threshold. Whereas for there are no bounded orbits, and for there is just one closed orbit, for the bounded orbits form a Cantor set. We analyze the symbolic dynamics and estimate Hausdorff dimension and topological entropy of this hyperbolic set....
The orbits about an oblate spheroid
Théorie des perturbations de la Lune qui sont dues à l'action des planètes.
Triple Collision in the Collinear Three-Body Problem.