... dynamical systems, ” inStochastics, Algebra and Analysis in Classical and Quantum Dynamics (Marseille, 1988), vol. 59 of Math.Appl., pp. 211–223, Kluwer Acad. Publ., Dordrecht, The Netherlands, ... Zhang and J. Xu, “Gevrey-smoothness of elliptic lower-dimensional invariant tori in Hamiltonian systems under R¨ussmann’s non-degeneracy condition,” Journal of Mathematical Analysis andApplications, ... itfrom another KAM theorem, which is concerned with perturbations of a family of linear Hamiltonians. This is accomplished by introducing a parameter and changing theHamiltonian system 1.3 to a...