A hybrid Lagrangian-Hamiltonian framework and its application to conserved integrals and symmetry groups
Abstract
A hybrid framework is developed that highlights and unifies the most important aspects of the Noether correspondence between symmetries and conserved integrals in Lagrangian and Hamiltonian mechanics. Several main results are shown: (1) a modern form of Noether's theorem is presented that uses only the equations of motion, with no knowledge required of an explicit Lagrangian; (2) the Poisson bracket is formulated with Lagrangian variables and used to express the action of symmetries on conserved integrals; (3) features of point symmetries versus dynamical symmetries are clarified and explained; (4) both autonomous and non-autonomous systems are treated on an equal footing. These results are applied to dynamical systems that are locally Liouville integrable. In particular, they allow finding the complete Noether symmetry group of such systems.
Cite
@article{arxiv.2603.03487,
title = {A hybrid Lagrangian-Hamiltonian framework and its application to conserved integrals and symmetry groups},
author = {Stephen C. Anco},
journal= {arXiv preprint arXiv:2603.03487},
year = {2026}
}
Comments
26 pages: addition of material on Liouville integrable systems and remarks on complete integrability/superintegrability