SYMPLECTIC INTEGRATOR FOR GENERAL NEAR-INTEGRABLE HAMILTONIAN SYSTEM

In this paper, following the idea of constructing the mixed symplectic integrator (MSI) for a separable Hamiltonian system, we give a low or der mixed symplectic integrator for an inseparable, but nearly integra ble, Hamiltonian system. Although the difference schemes of the integr ators are implicit, they not only have a small truncation error but, d ue to near integrability, also a faster convergence rate of iterative solution than ordinary implicit integrators. Moreover, these second or der integrators are time-reversible.