Published online by Cambridge University Press: 20 November 2018
Let $G$ be a finite group acting linearly on the vector space $V$ over a field of arbitrary characteristic. The action is called coregular if the invariant ring is generated by algebraically independent homogeneous invariants, and the direct summand property holds if there is a surjective $k{{[V]}^{G}}$-linear map $\pi \,:\,k[V]\,\to \,k{{[V]}^{G}}$.
The following Chevalley–Shephard–Todd type theorem is proved. Suppose $G$ is abelian. Then the action is coregular if and only if $G$ is generated by pseudo-reflections and the direct summand property holds.