Yang-Mills action
= Yang-Mills action
{c}
{title2=$S_{\rm YM}$}
On an oriented Riemannian four-manifold, one positive Euclidean convention is
$$
S_{\rm YM}=-\frac1{g_{\rm YM}^2}
\int\operatorname{Tr}(F\wedge{}^\star F)
$$
for anti-Hermitian gauge fields.