Galois extensions, plus closure, and maps on local cohomology

Given a local domain (R, m) of prime characteristic that is a homomorphic image of a Gorenstein ring, Huneke and Lyubeznik proved that there exists a module-finite extension domain S such that the induced map on local cohomology modules H-m(i) (R) --> H-m(i) (S) is zero for each i < dim R. We prove that the extension S may be chosen to be generically Galois, and analyze the Galois groups that arise. (C) 2011 Elsevier Inc. All rights reserved.