Week 6

Session 1

Pre-class videos

Pre-class exercises

Exercise:

Compute the action of \mathrm{Sym}^2(Y) on the basis e_1^2, e_1e_2, e_2^2.

Exercise:

Check that X Y to the k v equals (m plus 1 minus k plus 1) times (k minus 1) Y to the k minus 1, plus (m minus 2 k plus 2) Y to the k minus 1 v, simplifies to give X Y to the k v equals (m plus 1 minus k), times k, times Y to the k minus 1 v.

Session 2

Pre-class videos

Pre-class exercises

Exercise:

Compute the weight diagrams and decomposition of \mathrm{Sym}^k(\CC^2)\otimes\mathrm{Sym}^\ell(\CC^2) for a few different values of k and \ell and see if you can formulate a conjecture as to what the answer should be in general.

Optional extras