IAS CMP/QFT Group Meeting

Abstract: In this talk, I will explore a variety of 1+1d lattice models exhibiting anti-unitary symmetries that simultaneously reflect space and reverse time. These symmetries can be anomalous, leading to Lieb-Schultz-Mattis-type constraints that forbid a trivially gapped, symmetric phase. I will present examples such as the mod 8 anomaly in the Majorana chain and various mod 2 anomalies in spin chains. A central theme will be the fate of these symmetries in the continuum: in some models, an exact lattice symmetry flows to continuum CPT symmetry, while in others, CPT symmetry is emergent, or even absent entirely. I will discuss how the anomalies of the lattice models are matched in the continuum, including instances where they map to emergent anomalies of emanant symmetries.