Equivariant class group. II. Enriched descent theorem
  We prove a version of Grothendieck's descent theorem on an `enriched' principal fiber bundle, a principal fiber bundle with an action of a larger group scheme. Using this, we prove the isomorphisms of the equivariant Picard and the class groups arising from such a principal fiber bundle. 
Mitsuyasu Hashimoto
math.AC math.AG