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arXiv · 1808.03489

On the trace anomaly of a Weyl fermion in a gauge background

Fiorenzo Bastianelli·Matteo Broccoli
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Abstract

We study the trace anomaly of a Weyl fermion in an abelian gauge background. Although the presence of the chiral anomaly implies a breakdown of gauge invariance, we find that the trace anomaly can be cast in a gauge invariant form. In particular, we find that it does not contain any odd-parity contribution proportional to the Chern-Pontryagin density. The latter would be allowed by the consistency conditions. We perform our calculations using Pauli-Villars regularization and heat kernel methods. The issue is analogous to the one recently discussed in the literature about a conjectured contribution of an odd-parity term to the trace anomaly of a Weyl fermion in curved backgrounds.

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Fiorenzo Bastianelli, Matteo Broccoli. 2018-08-10. On the trace anomaly of a Weyl fermion in a gauge background. https://doi.org/10.1140/epjc/s10052-019-6799-z

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