Determining a connected split reductive group from its irreducible representations

Abstract

We show that a connected split reductive group G over a field of characteristic 0 is determined up to isomorphism by specifying a maximal torus T of G, the set of isomorphism classes of irreducible representations of G, and the character homomorphism from the Grothendieck ring of G to that of T. More precisely, we determine all isomorphisms compatible with the specified data. © © de Gruyter 2008 2008.