Lie groupoids in classical field theory I: Noether’s theorem

Abstract

In the two papers of this series, we initiate the development of a new approach to implementing the concept of symmetry in classical field theory, based on replacing Lie groups/algebras by Lie groupoids/algebroids, which are the appropriate mathematical tools to describe local symmetries when gauge transformations are combined with space–time transformations. Here, we outline the basis of the program and, as a first step, show how to (re)formulate Noether’s theorem about the connection between symmetries and conservation laws in this approach.