The purpose of this paper is to describe geometrically discrete Lagrangian
and Hamiltonian Mechanics on Lie groupoids. From a variational principle we
derive the discrete Euler-Lagrange equations and we introduce a symplectic
2-section, which is preserved by the Lagrange evolution operator. In terms of
the discrete Legendre transformations we define the Hamiltonian evolution
operator which is a symplectic map with respect to the canonical symplectic
2-section on the prolongation of the dual of the Lie algebroid of the given
groupoid. The equations we get include as particular cases the classical
discrete Euler-Lagrange equations, the discrete Euler-Poincar\'e and discrete
Lagrange-Poincar\'e equations. Our results can be important for the
construction of geometric integrators for continuous Lagrangian systems.
@article{0506299,
author = {Marrero, J. C. and de Diego, D. Mart\'\i n and Mart\'\i nez, E.},
title = {Discrete Lagrangian and Hamiltonian Mechanics on Lie groupoids},
journal = {arXiv},
volume = {2005},
number = {0},
year = {2005},
language = {en},
url = {http://dml.mathdoc.fr/item/0506299}
}
Marrero, J. C.; de Diego, D. Martín; Martínez, E. Discrete Lagrangian and Hamiltonian Mechanics on Lie groupoids. arXiv, Tome 2005 (2005) no. 0, . http://gdmltest.u-ga.fr/item/0506299/