BRST Noether Theorem and Corner Charge Bracket

TL;DR

This paper proves a generalized BRST Noether theorem for a wide class of gauge theories, revealing the structure of conserved charges and introducing a new bracket to handle non-integrability issues in asymptotic symmetries.

Contribution

It extends the BRST Noether theorem to include corner charges and introduces a novel charge bracket for non-integrable charges in gauge theories.

Findings

Decomposition of BRST currents into exact and corner terms

Universal gauge-independent derivation of S-matrix invariance

Introduction of a new charge bracket for non-integrable charges

Abstract

We provide a proof of the BRST Noether 1.5th theorem, conjectured in [JHEP 10 (2024) 055], for a broad class of rank-1 BV theories including supergravity and 2-form gauge theories. The theorem asserts that the BRST Noether current of any BRST invariant gauge fixed Lagrangian decomposes on-shell into a sum of a BRST-exact term and a corner term that defines Noether charges. This extends the holographic consequences of Noether's second theorem to gauge fixed theories and, in particular, offers a universal gauge independent Lagrangian derivation of the invariance of the S-matrix under asymptotic symmetries. Furthermore, we show that these corner Noether charges are inherently non-integrable. To address this non-integrability, we introduce a novel charge bracket that accounts for potential symplectic flux and anomalies, providing an honest canonical representation of the asymptotic symmetry algebra. We also highlight a general origin of a BRST cocycle associated with asymptotic symmetries.