Paper 4, Section II, G

Representation Theory
Part II, 2017

Let G=SU(2)G=\mathrm{SU}(2) and let VnV_{n} be the vector space of complex homogeneous polynomials of degree nn in two variables.

(a) Prove that VnV_{n} has the structure of an irreducible representation for GG.

(b) State and prove the Clebsch-Gordan theorem.

(c) Quoting without proof any properties of symmetric and exterior powers which you need, decompose S2Vn\mathrm{S}^{2} V_{n} and Λ2Vn(n1)\Lambda^{2} V_{n}(n \geqslant 1) into irreducible GG-spaces.