Take a real vector space R transforming in the adjoint representation of the E7(7) Lie group as R-> G R G^-1. One can define invariants using traces of products of R as Tr[R^k].

I heard that a basis of invariants is given by k=2,6,8,10,12,14,18. Is it correct? Which is the theorem with that statement?

Thanks for your help

Take a real vector space $R$ transforming in the adjoint representation of the ${\rm E}_7(7)$ Lie group as $R \rightarrow G R G^{-1}$. One can define invariants using traces of products of $R$ as ${\rm Tr}[R^k]$.

I heard that a basis of invariants is given by $k = 2,6,8,10,12,14,18$. Is this correct? Which theorem states this?

Thanks for your help