Geometric numerical methods for mechanics
Résumé
In this paper, two classes of numerical integrators are introduced and compared : Lie group methods, presented via the particular case of Runge-Kutta Munthe-Kaas integrators ; and variational methods, in which natural charts integrators and Galerkin methods are examined. Considering the case of a configuration manifold with a Lie group action, both classes of methods are studied in terms of configuration space preservation and symplectic/energy behaviour. As an example, we apply those formulations on the rigid body problem.