Anomalies of non-Abelian finite groups via cobordism

Davighi, Joe; Gripaios, Ben; Lohitsiri, Nakarin

Abstract

We use cobordism theory to analyse anomalies of finite non-abelian symmetries in 4 spacetime dimensions. By applying the method of ‘anomaly interplay’, which uses functoriality of cobordism and naturality of the η-invariant to relate anomalies in a group of interest to anomalies in other (finite or compact Lie) groups, we derive the anomaly for every representation in many examples motivated by flavour physics, including S3, A4, Q8, and SL(2, 𝔽3). In the case of finite abelian groups, it is well known that anomalies can be ‘truncated’ in a way that has no effect on low-energy physics, by means of a group extension. We extend this idea to non-abelian symmetries. We show, for example, that a system with A4 symmetry can be rendered anomaly-free, with only one-third as many fermions as naïvely required, by passing to a larger symmetry. As another example, we find that a well-known model of quark and lepton masses utilising the SL(2, 𝔽3) symmetry is anomalous, but that the anomaly can be cancelled by enlarging the symmetry to a ℤ/3 extension of SL(2, 𝔽3).

Citation

Davighi, J., Gripaios, B., & Lohitsiri, N. (2022). Anomalies of non-Abelian finite groups via cobordism. Journal of High Energy Physics, 2022(9), Article 147. https://doi.org/10.1007/jhep09%282022%29147

• Journal Article Type: Article
• Acceptance Date: Sep 6, 2022
• Online Publication Date: Sep 19, 2022
• Publication Date: 2022
• Deposit Date: Oct 27, 2022
• Publicly Available Date: Oct 27, 2022
• Journal: Journal of High Energy Physics
• Print ISSN: 1126-6708
• Electronic ISSN: 1029-8479
• Publisher: Scuola Internazionale Superiore di Studi Avanzati (SISSA)
• Peer Reviewed: Peer Reviewed
• Volume: 2022
• Issue: 9
• Article Number: 147
• DOI: https://doi.org/10.1007/jhep09%282022%29147
• Public URL: https://durham-repository.worktribe.com/output/1190322