Explicit, time reversible, adaptive step size control
Ernst Hairer and Gustaf Söderlind
Abstract.
Adaptive step size control is difficult to combine with geometric
numerical integration. As classical step size control is based on
``past'' information only, time symmetry is destroyed and with it
also the qualitative properties of the method. In this paper we
develop completely explicit, reversible and symmetry preserving,
adaptive step size selection algorithms for geometric numerical
integrators such as the St\"ormer--Verlet method. A new step
density controller is proposed and analyzed using backward error
analysis and reversible perturbation theory. For integrable
reversible systems we show that the resulting adaptive method
nearly preserves all action variables and, in particular, the total energy for
Hamiltonian systems. It has the same excellent long term
behaviour as if constant steps were used. With variable steps,
however, both accuracy and efficiency are greatly improved.
Key Words.
Adaptive integration, geometric integration, time reversible and symmetric
methods, St\"ormer--Verlet method, Hamiltonian systems,
explicit and reversible step size control,
backward error analysis, reversible perturbation theory.