Generalised Symmetries, Anomalies, and Maximal Branches of 3d Chern-Simons Matter Theories

Abstract

The generalised symmetries, 't Hooft anomalies, and their interplay with maximal branches are analysed for linear unitary three-dimensional $\mathcal{N}\geq 3$ Chern-Simons Matter quiver theories realised in Type IIB brane configurations. The 1-form symmetry, its self-anomaly and its maximal anomaly-free subgroup are determined independently from Wilson-line screening and from the string lattice. Fractional monopole endpoints of the generating Gukov-Witten defect are used to extract the anomaly data, while centre charges of integer monopoles determine the faithful 0-form symmetry group, its connected cover and possible 2-group structures. Mixed anomalies with non-abelian 0-form factors are found to cancel in the linear unitary theories considered. The effect of 1-form gauging on maximal branches is related to frozen D3-brane sectors, which flow to Chern-Simons TQFTs whose anyonic lines obstruct the required defect endpoint. This yields a criterion for affected branches and implies that at most two can be affected simultaneously. In such a case, a magnetic-quiver extension by non-simply laced edges is proposed, wherein the 1-form symmetry and its mixed anomaly with the branch isometry are reproduced.