Noether identities

Noether identities are a set of relations that arise in the context of Lagrangian field theories, particularly in relation to symmetries and conservation laws as formulated by the mathematician Emmy Noether. These identities are closely tied to Noether's theorem, which states that every continuous symmetry of the action of a physical system corresponds to a conservation law. Noether identities typically arise when dealing with gauge theories or systems with constraints and play an important role in ensuring the consistency of the theory.