Triangulations and Severi varieties
  We consider the problem of constructing triangulations of projective planes over Hurwitz algebras with minimal numbers of vertices. We observe that the numbers of faces of each dimension must be equal to the dimensions of certain representations of the automorphism groups of the corresponding Severi varieties. We construct a complex involving these representations, which should be considered as a geometric version of the (putative) triangulations. 
Fr\'ed\'eric Chapoton (ICJ), Laurent Manivel (IF)
math.AG math.AT math.CO math.RT