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arXiv · 2507.16966

Higher symmetries, anomalies, and crossed squares in lattice gauge theory

Anton Kapustin·Lev Spodyneiko
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Abstract

We examine higher-form symmetries of quantum lattice gauge theories through the lens of homotopy theory and operator algebras. We show that in the operator-algebraic approach both higher-form symmetries and 't Hooft anomalies arise from considering restrictions of symmetry transformations to spatial regions. The data of these restrictions are naturally packaged into a higher group. For example, for gauge theories in two spatial dimensions, this information is encoded in a crossed square of groups, which is an algebraic model of a 3-group. In general, we propose that higher groups appear in lattice models and QFT as crossed n-cubes of groups via a nonabelian version of the Cech construction.

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Anton Kapustin, Lev Spodyneiko. 2025-07-22. Higher symmetries, anomalies, and crossed squares in lattice gauge theory. https://arxiv.org/abs/2507.16966

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