Speaker
Description
We study non-invertible defects constructed from dualities in the Cardy-Rabinovici model. The Cardy-Rabinovici model is a four-dimensional $U(1)$ lattice gauge theory with both electrically and magnetically charged particles, which is used as a playground for investigating the dynamics of the Yang-Mills theory with $\theta$ angle. A notable feature of this model is that the conjectured phase diagram has the electromagnetic $SL(2, \mathbb{Z})$ invariance generated by $S$ and $T$ transformations. Although this model does not enjoy the $SL(2, \mathbb{Z})$ duality in a naive way, we notice that the $SL(2, \mathbb{Z})$ transformations can be understood as dualities between the Cardy-Rabinovici model and $\mathbb{Z}_N$ 1-form gauged one. Based on this observation, we construct non-invertible symmetries and determine their non-group-like fusion rules in a formal continuum description of the Cardy-Rabinovici model. Moreover, for some self-dual points, we find that this symmetry turns out to have a mixed gravitational anomaly, which rules out the trivially gapped phase. We also address how the conjectured phase diagram matches this anomaly. This talk is based on arXiv:2204.07440 [hep-th].
