Ruumgrupid
Ruumgrupid, also known as room groups, are mathematical structures used in the study of Lie groups and Lie algebras. They are finite groups that act on a vector space, preserving a bilinear form. This bilinear form is typically symmetric or skew-symmetric, and it is invariant under the action of the group. Ruumgrupid are classified by their rank, which is the dimension of a maximal commutative subalgebra of the Lie algebra associated with the group. The classification of Ruumgrupid is a fundamental problem in the theory of Lie groups and Lie algebras, and it has been extensively studied by mathematicians. The most well-known Ruumgrupid are the Weyl groups, which are associated with the classical Lie groups and Lie algebras. These groups play a crucial role in the representation theory of Lie groups and Lie algebras, and they have numerous applications in physics and other fields.