Chern-Simons current
= Chern-Simons current
{c}
{title2=$K^\mu$}
{wiki=Chern–Simons_form}
The Chern-Simons current satisfies $\partial_\mu K^\mu=\operatorname{Tr}(F_{\mu\nu}{}^\star F^{\mu\nu})$. It is not gauge invariant even though its divergence is.