SO(N) gauge theories in D=2+1 and D=3+1
We investigate the physics of SO(N) gauge theories in 3 and 4 dimensions, and compare with SU(N). One motivation is the large-N orbifold equivalence between SO(2N) and SU(N) which has motivated novel ways to finesse the QCD `sign problem’ at finite chemical potential. The differing centre properties of SO(N) and SU(N) provides another motivation.