Research project of the Research Foundation - Flanders (2010 - 2013)

Description of the project

The role that symmetry properties of a dynamical system play in its reduction to a (possibly) simpler system, and in the stability properties of certain of its solutions, is an important field of research. Whereas this topic has already been extensively dealt with in the case of Hamiltonian systems in a symplectic or, more generally, a Poisson context , the Lagrangian side of the story has always received much less attention in the literature. The goal of this project therefore is to restore this balance in some sense by analyzing symmetry and reduction aspects in the context of Lagrangian dynamical systems. In particular, attention will be focused on so-called Routh reduction and Routh reduction by stages for invariant and quasi-invariant Lagrangian systems. The techniques will be illustrated on some concrete mechanical systems such as, for instance, a rigid body submerged in a fluid. The stability of relative equilibria will also be investigated in a Lagrangian setting. Finally, the extent to which the symmetry and reduction techniques for Lagrangian and Hamiltonian systems can be modified or generalized in order to apply them to systems with non-holonomic constraints and to (non-Lagrangian) systems with dissipation, will also be investigated.

Researchers involved with the project

Promotor: Frans Cantrijn (

Co-promotor: Bavo Langerock (

Willy Sarlet (

Tom Mestdag (

Joris Vankerschaver (

Eduardo García-Toraño

International collaboration with:


B. Langerock and M. Castrillón López, Routh reduction for singular Lagrangians, IJGMMP 7(8), 1451--1489 (2010).
[ArXiv] [doi]

B. Langerock, F. Cantrijn, J. Vankerschaver. Routhian reduction for quasi-invariant Lagrangians. J. Math. Phys. 51 (2010) 022902. [abs] [pdf] [doi]

Department of MathematicsDepartment of Mathematics