Normality of maximal orbit closures for Euclidean quivers
  Let Delta be an Euclidean quiver. We prove that the closures of the maximal orbits in the varieties of representations of Delta are normal and Cohen--Macaulay (even complete intersections). Moreover, we give a generalization of this result for the tame concealed-canonical algebras. 
Grzegorz Bobinski
math.RT