(Non-)Abelian discrete anomalies
Takeshi Araki, Tatsuo Kobayashi, Jisuke Kubo, Saul Ramos-Sanchez, Michael Ratz, Patrick K. S. Vaudrevange
TL;DR
This work derives anomaly constraints for both Abelian and non-Abelian discrete symmetries using a path-integral (Fujikawa) approach and applies them to heterotic orbifold models, where discrete anomalies are shown to originate from the anomalous $U(1)$ and its geometric counterpart, the anomalous space-group element. The authors demonstrate universal Green-Schwarz cancellation of basic anomalies and reveal intricate relations among $k$-anomalies, flavor, $R$-symmetries, and $T$-duality anomalies, including connections to $T$-dependent threshold corrections. They also discuss how FI-term cancellation in supersymmetric vacua generically breaks anomalous $U(1)$ and often the associated discrete symmetries, with potential implications for the emergence of approximate flavor structures. Overall, the results provide a structured map from geometric/auxiliary string data to low-energy discrete anomalies and their consistent cancellation mechanisms, offering guidance for string-model building and phenomenology of approximate symmetries.
Abstract
We derive anomaly constraints for Abelian and non-Abelian discrete symmetries using the path integral approach. We survey anomalies of discrete symmetries in heterotic orbifolds and find a new relation between such anomalies and the so-called `anomalous' U(1).
