I have the following question: Let $R \subset \Lambda^{*}\mathbb{R}^{2n}$ be the sub-ring of forms which are preserved by $SU(n)$. How can one show that this subring is generated by $\Omega_{0}$ and $\omega_0$ where $\Omega_{0}=dz^{1}\wedge ... \wedge dz^{n}$ and $\omega_{0}=\frac{i}{2}\sum_{i=1}^{n}dz^{i}\wedge d\overline{z}^{i}$?
monica