Finite-dimensional vertex algebra modules over fixed point commutative subalgebras

Let A be a connected commutative C-algebra with derivation D, G a finite linear automorphism group of A which preserves D, and R=AG the fixed point subalgebra of A under the action of G. We show that if A is generated by a single element as an R-algebra and is a Galois extension over R in the sense of M. Auslander and O. Goldman, then every finite-dimensional indecomposable vertex algebra R-module has a structure of twisted vertex algebra A-module.