Comments on Global Symmetries, Anomalies, and Duality in (2+1)d

Understand

We analyze in detail the global symmetries of various (2+1)d quantum field theories and couple them to classical background gauge fields.

• A proper identification of the global symmetries allows us to consider all non-trivial bundles of those background fields, thus finding more subtle observables.
• The global symmetries exhibit interesting 't Hooft anomalies.
• These allow us to constrain the IR behavior of the theories and provide powerful constraints on conjectured dualities.