Dan Abramovich, Alessio Corti, Angelo Vistoli. Twisted Bundles and Admissible Covers. Communications in Algebra. 2003.
Abstract
We study the structure of the stacks of twisted stable maps to the classifying stack of a finite group G–-which we call the stack of twisted G-covers, or twisted G-bundles. For a suitable group Gwe show that the substack corresponding to admissible G-covers is a smooth projective fine moduli space. Dedicated to Steven L. Kleiman on the occasion of his 60th birthday. Dedicated to Steven L. Kleiman on the occasion of his 60th birthday.