Representation rings of semidirect products of tori by finite groups

• Main Author: Stykow, Maxim
• Language: English
• Published: University of British Columbia 2015
• Online Access: http://hdl.handle.net/2429/54513

This dissertation studies semidirect products of a torus by a finite group from the representation theory point of view. The finite group of greatest interest is the cyclic group of prime order. Such semidirect products occur in nature as isotropy groups of Lie groups acting on themselves by conjugation and as normalizers of maximal tori in reductive linear algebraic groups. The main results of this dissertation are: a) the calculation of the representation ring of such semidirect products as an algebra over the integers for certain special cases, b) the adaptation of an algorithm from invariant theory to find finite presentations of representation rings, c) the computation of the topological K-theory of the classifying space of certain semidirect products, d) the demonstration that the equivariant K-theory of the projective unitary group of degree 2 acting on itself by conjugation is not a free module over its representation ring. === Science, Faculty of === Mathematics, Department of === Graduate