In mathematics, an exceptional Lie algebra is a complex simple Lie algebra whose Dynkin diagram is of exceptional (nonclassical) type.
[2] The corresponding diagrams are:[3] In contrast, simple Lie algebras that are not exceptional are called classical Lie algebras (there are infinitely many of them).
There is no simple universally accepted way to construct exceptional Lie algebras; in fact, they were discovered only in the process of the classification program.
This algebra-related article is a stub.
You can help Wikipedia by expanding it.