Paper 3, Section II, F

Representation Theory
Part II, 2009

Let G=SU(2)G=\mathrm{SU}(2). Let VnV_{n} be the complex vector space of homogeneous polynomials of degree nn in two variables z1,z2z_{1}, z_{2}. Define the usual left action of GG on VnV_{n} and denote by ρn:GGL(Vn)\rho_{n}: G \rightarrow \operatorname{GL}\left(V_{n}\right) the representation induced by this action. Describe the character χn\chi_{n} afforded by ρn\rho_{n}.

Quoting carefully any results you need, show that

(i) The representation ρn\rho_{n} has dimension n+1n+1 and is irreducible for nZ0n \in \mathbb{Z}_{\geqslant 0};

(ii) Every finite-dimensional continuous irreducible representation of GG is one of the ρn\rho_{n};

(iii) VnV_{n} is isomorphic to its dual VnV_{n}^{*}.