The super Frobenius-Schur indicator and finite group gauge theories on pin${}^{-}$ surfaces

Takumi Ichikawa, Yuji Tachikawa

It is well-known that the value of the Frobenius-Schur indicator $|G{|}^{-1}{\sum }_{g\in G}\chi (g^2)=\pm 1$ of a real irreducible representation of a finite group $G$ determines which of…