Persistence of Invariant Tori on Submanifolds in Hamiltonian Systems.

Discusses the persistence of invariant tori on submanifolds in Hamiltonian systems. Use of a quasilinear iterative scheme; Nondegenerate condition of Russmann type on the manifold; Persistence of the majority of the unperturbed tori on the manifold; Partial preservation of perturbed total frequencies according to the maximal degeneracy of the Hessian of the unperturbed system.