Symmetric and symplectic exponential integrators for nonlinear Hamiltonian systems
For researchers in numerical integration of Hamiltonian systems, this work provides new integrators with improved numerical behavior, though it is an incremental extension of known methods.
The authors derived symmetric and symplectic exponential integrators for nonlinear Hamiltonian systems, establishing conditions for symmetry and symplecticity that extend Runge-Kutta methods. Numerical experiments showed that the new integrators up to order four outperform existing symmetric and symplectic Runge-Kutta methods.
This letter studies symmetric and symplectic exponential integrators when applied to numerically computing nonlinear Hamiltonian systems. We first establish the symmetry and symplecticity conditions of exponential integrators and then show that these conditions are extensions of the symmetry and symplecticity conditions of Runge-Kutta methods. Based on these conditions, some symmetric and symplectic exponential integrators up to order four are derived. Two numerical experiments are carried out and the results demonstrate the remarkable numerical behavior of the new exponential integrators in comparison with some symmetric and symplectic Runge-Kutta methods in the literature.