We review two related notions of index introduced by Dynkin, one the index of a subgroup or subalgebra in a semi-simple group or algebra and the other being the index of a linear representation of a semi-simple Lie algebra. Amongst other results we give a simple algebraic proof of Dynkin's theorem that this first index is an integer.
|Number of pages||11|
|Journal||Journal of the London Mathematical Society|
|Publication status||Published - Apr 1991|