Line Defect Quantum Numbers and Anomalies

          @misc{ scivideos_PIRSA:22060021,
            doi = {10.48660/22060021},
            url = {https://pirsa.org/22060021},
            author = {Dumitrescu, Thomas},
            keywords = {Mathematical physics},
            language = {en},
            title = {Line Defect Quantum Numbers and Anomalies},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2022},
            month = {jun},
            note = {PIRSA:22060021 see, \url{https://scivideos.org/index.php/pirsa/22060021}}
          }
          

Abstract

I will consider four-dimensional gauge theories whose global symmetries admit certain discrete ’t Hooft anomalies that are intimately related to the (fractionalized) global-symmetry quantum numbers of Wilson-’t Hooft line defects in the theory. Determining these quantum numbers is typically straightforward for Wilson lines, but requires a careful analysis of fermion zero modes for ’t Hooft lines, which I will describe for several classes of examples. This in turn leads to a calculation of the anomaly. Along the way I will comment on how this understanding relates to some classic and recent examples in the literature.