Hard balls gas and Alexandrov spaces of curvature bounded above.
Integral manifolds of the N-body problem.
Le formalisme de contact en mécanique classique et relativiste
Le problème des corps unidimensionnel et le mouvement rectiligne des gaz
Minimization properties of Hill's orbits and applications to some N-body problems
Morse index properties of colliding solutions to the N-body problem
-body problem in : necessary conditions for a constant configuration measure.
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.
Periodic solutions for N-body type problems
Periodic solutions with prescribed energy for some keplerian -body problems
Problème diophantien des moments et modèle d'Ising
Problème diophantien des moments et modèle d'Ising
Pyramidal central configurations and perverse solutions.