Invariants of normal local rings by p-cyclic group actions
arXiv:1001.1945
Abstract
Let be a Noetherian normal local ring, and $G\subset\Aut(B)$ a cyclic group of local automorphisms of prime order. Let be the ring of -invariants of , assume that is Noetherian. We study the invariant morphism; in particular, we prove that is a monogenous -algebra if and only if the augmentation ideal of is principal. If in particular is regular, we prove that is regular if the augmentation ideal of is principal.