title: Itô's theorem
text: # Itô's theorem
  
  Itô's theorem is a result in the mathematical discipline of representation theory due to Noboru Itô. It generalizes the well-known result that the dimension of an irreducible representation of a group must divide the order of that group.
  
  ## Statement
  
  Given an irreducible representation V of a finite group G and a maximal normal abelian subgroup A ⊆ G, the dimension of V must divide [G:A].
  
  