On central configurations.
On non-existence of periodic solutions of an important differential equation
On the geometry and behavior of -body motions.
On the Integral Manifolds of the N-Body Problem.
On the mobility and efficiency of mechanical systems
It is shown that self-locomotion is possible for a body in Euclidian space, provided its dynamics corresponds to a non-quadratic Hamiltonian, and that the body contains at least 3 particles. The efficiency of the driver of such a system is defined. The existence of an optimal (most efficient) driver is proved.
On the real singularities of the N-body problem.
On the Singularities of the Newtonian two dimensional N-body Problem
Si considera un sistema bidimensionale di particelle interagenti tramite un potenziale di Newton o di Coulomb e si mostra che l’insieme delle condizioni iniziali che in un tempo finito possono condurre a delle singolarità possiede misura di Lebesgue nulla.
One-dimensional motion of balls.