Weak in the boundary: How weak SPT phases spoil anomaly matching
arXiv:2507.17179
Abstract
We show how weak symmetry protected topological (SPT) phases on systems with a boundary are not in 1-to-1 correspondence with weak SPT phases on fully periodic systems, breaking the standard anomaly inflow interpretation of SPT phases. We further discuss the implications for the crystalline equivalence principle (CEP).
Accepted for Publication in PRB