Auslander's Theorem for dihedral actions on preprojective algebras of type A
arXiv:2108.08939 · doi:10.4153/S0008439522000364
Abstract
Given an algebra and a finite group of automorphisms of , there is a natural map , called the Auslander map. A theorem of Auslander shows that is an isomorphism when and is a finite group acting linearly and without reflections on the finite-dimensional vector space . The work of Mori and Bao-He-Zhang has encouraged study of this theorem in the context of Artin-Schelter regular algebras. We initiate a study of Auslander's result in the setting of non-connected graded Calabi-Yau algebras. When is a preprojective algebra of type and is a finite subgroup of acting on by automorphism, our main result shows that is an isomorphism if and only if does not contain all of the reflections through a vertex.
Some typos fixed. To appear in Canadian Mathematical Bulletin