ABJ anomaly as a U(1) symmetry and Noether's theorem

Sep 6, 2023
Published in:
  • SciPost Phys. 18 (2025) 041
e-Print:

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202220232024017
Abstract: (arXiv)
The Adler-Bell-Jackiw anomaly determines the violation of chiral symmetry when massless fermions are coupled to an abelian gauge field. In its seminal paper, Adler noticed that a modified chiral U(1) symmetry could still be defined, at the expense of being generated by a non-gauge-invariant conserved current. We show this internal U(1) symmetry has the special feature that it transforms the Haag duality violating sectors (or non-local operator classes). This provides a simple unifying perspective on the origin of anomaly quantization, anomaly matching, applicability of Goldstone theorem, and the absence of a Noether current. We comment on recent literature where this symmetry is considered to be either absent or non-invertible. We end by recalling the DHR reconstruction theorem, which states 0-form symmetries cannot be non-invertible for d>2, and argue for a higher-form symmetry reconstruction theorem.
Note:
  • To appear in SciPost Physics
  • symmetry: U(1)
  • operator: nonlocal
  • fermion: massless
  • duality: violation
  • symmetry: chiral
  • current: Noether
  • current: conservation law
  • gauge field theory: abelian
  • anomaly
  • Goldstone theorem