IAS CMP/QFT Group Meeting

Abstract: We introduce stratified symmetry operators and stratified anomalies, which generalize onsite symmetry operators and onsite projective representations in quantum lattice systems. A stratified symmetry operator is a symmetry operator that decomposes into a collection of mutually independent subsystem symmetry operators, and its stratified anomaly is the collection of 't Hooft anomalies of its constituent subsystem operators. We will discuss the stratified anomalies of modulated symmetries and show how they give rise to Lieb-Schultz-Mattis (LSM) constraints. Notably, for modulated symmetries, a nontrivial stratified anomaly within a unit cell does not necessarily imply an LSM constraint.