Discrete dynamics in implicit form
arXiv:1011.3724
Abstract
A notion of implicit difference equation on a Lie groupoid is introduced and an algorithm for extracting the integrable part (backward or/and forward) is formulated. As an application, we prove that discrete Lagrangian dynamics on a Lie groupoid may be described in terms of Lagrangian implicit difference equations of the corresponding cotangent groupoid . Other situations include finite difference methods for time-dependent linear differential-algebraic equations and discrete nonholonomic Lagrangian systems, as particular examples.
22 pages, several examples have been included, abstract and introduction have been modified, added references