Model-independent results on parity violation in the trace anomaly

Rémy Larue; Jérémie Quevillon; Roman Zwicky

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arXiv · 2411.00571

Model-independent results on parity violation in the trace anomaly

Rémy Larue·Jérémie Quevillon·Roman Zwicky

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Abstract

Anomalous parity violation in four dimensions would be significant for phenomenology (baryogenesis, gravitational waves) and mathematical physics. Over the past decade, there has been a controversy in the literature as to whether free Weyl fermions give rise to (anomalous) parity violation in the trace of the energy momentum tensor; expressed by the Pontryagin densities $R\tilde R$ and $F\tilde F$ in the gravity and the gauge sector respectively. In Ref.$^1$, we have shown, using path integral methods, that the trace anomaly of a free Weyl fermion does not violate parity (i.e the absence of the Pontryagin density). In a subsequent work$^2$ we came to the stronger conclusion that for any theory compatible with dimensional regularisation, the Pontryagin-terms are equally absent. It is the \textit{finiteness} of the diffeomorphism, the Lorentz and the gauge anomalies that prevents anomalous parity violation.

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Rémy Larue, Jérémie Quevillon, Roman Zwicky. 2024-11-01. Model-independent results on parity violation in the trace anomaly. https://arxiv.org/abs/2411.00571

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