Deforming group actions on Koszul algebras
  We give Braverman-Gaitsgory style conditions for general PBW deformations of skew group algebras formed from finite groups acting on Koszul algebras. When the characteristic divides the order of the group, this includes deformations of the group action as well as of the Koszul relations. 
Anne V. Shepler and Sarah Witherspoon
math.RA math.RT