Recent results in the geometry of constrained systems
The paper presents a nice, comprehensive survey of the author's approach to the geometrical description of mechanical systems with nonholonomic constraints. This approach starts from the representation of an arbitrary system of second-order ordinary differential equations via a so-called dynamical form and its Lepage class on the second jet extension of a manifold fibred over a 1-dimensional base. The basic ingredients for such (unconstrained) dynamics are recalled in Section~2. Constraints are represented by a fibred submanifold \({\mathcal Q}\) of the first jet extension, leading to fundamental concepts such as the constraint ideal and the Chetaev bundle. An interesting result, quoted in Section~3, concerns the characterization of semi-holonomic constraints, for example by the property that the constraint ideal is a differential ideal. Semi-holonomic constraints turn out later (Section~6) to constitute the case in which the pullback of an unconstrained Lagrangian plays the role of Lagrangian for the constrained system. The main feature of this model is that constrained dynamical systems come from pulling back a representative of the Lepage class of a dynamical form to the constraint submanifold \({\mathcal Q}\). Constrained Lagrangian and Hamiltonian systems are discussed as particular cases within this general scheme.
scientific article; zbMATH DE number 1857362
scientific article