Copyright © 2000 Hindawi Publishing Corporation. All rights reserved.
The Motion of a Rigid Body in a Quadratic Potential: An Integrable Discretization
The motion of a rigid body in a quadratic potential is an important example of an integrable Hamiltonian system on a dual to a semidirect product Lie algebra
. We give a Lagrangian derivation of the corresponding equations of motion, and introduce a discrete time analog of this system. The construction is based on the discrete time Lagrangian mechanics on Lie groups, accompanied with the discrete time Lagrangian reduction. The resulting multi-valued map (correspondence) on the dual to
is Poisson with respect to the LiePoisson bracket, and is also completely integrable. We find a Lax representation based on matrix factorisations, in the spirit of Veselov and Moser.