Cartan's theorem
# Cartan's theorem

Cartan's theorem may refer to several mathematical results by Élie Cartan:

* Closed-subgroup theorem, 1930, that any closed subgroup of a Lie group is a Lie subgroup
* Theorem of the highest weight, that the irreducible representations of Lie algebras or Lie groups are classified by their highest weights
* Lie's third theorem, an equivalence between Lie algebras and simply-connected Lie groups
