Yang-Mills as massive Chern-Simons theory: a third way to three-dimensional gauge theories

Understand

The Yang-Mills (YM) equation in three spacetime dimensions (3D) can be modified to include a novel parity-preserving interaction term, with inverse mass parameter, in addition to a possible topological mass term.

• The novelty is that the modified YM equation is not the Euler-Lagrange equation of any gauge-invariant local action for the YM gauge potential alone.
• Instead, consistency is achieved in the "third way" exploited by 3D "minimal massive gravity".
• We relate our results to the "novel Higgs mechanism" for Chern-Simons gauge theories.