We discuss the topological terms, the global symmetries and their 't Hooft anomalies of pure gauge theories in various dimensions, with dynamical gauge group G, the Lorentz symmetry group G Lorentz , and the internal global symmetry G e,[1] × G m, [d−3] which consists of 1-form electric center symmetry G e,[1] and (d − 3) form magnetic symmetry G m, [d−3] . The topological terms are determined by the cobordism invariants (Ω d ) G ′ where G ′ is the group extension of G Lorentz by G, which also characterize the invertible TQFTs or SPTs with global symmetry G ′ . The 't Hooft anomalies are determined by the cobordism invariants (Ω d+1 ) G ′′ where G ′′ is the symmetry extension of G Lorentz by the higher form symmetry G e,[1] × G m, [d−3] . Different symmetry extensions correspond to different fractionalizations of G Lorentz quantum numbers on the symmetry defects of G e,[1] × G m, [d−3] . We compute the cobordism groups/invariants described above for G = U(1), SU(2) and SO(3) in d ≤ 5, thus systematically classifies all the topological terms and the 't Hooft anomalies of d dimensional quantum gauge theories with the above gauge groups.
December 2019W −