Forum of Mathematics Pi
An -valued index of symmetry-protected topological phases with on-site finite group symmetry for two-dimensional quantum spin systems
Yoshiko Ogata
Abstract
Abstract We consider symmetry-protected topological phases with on-site finite groupGsymmetry $\beta $ for two-dimensional quantum spin systems. We show that they have $H^{3}(G,{\mathbb T})$ -valued invariant.