# Homework Help: 4d representation of SO(3)

1. Apr 4, 2009

### negru

1. The problem statement, all variables and given/known data
Find the generators of the four dimensional irreducible representation of SO(3), such that J_3 is diagonal.

3. The attempt at a solution
I know how to get the rest if I know J_3, by using ladder operators. But what is J_3?
For a 3d representation it's diagonal with 1,0-1, in 4d would it be 3/2, 1/2, -1/2 -3/2? Wasn't orbital angular momentum supposed to be of integer values, or did I forget QM so bad?

Thanks for any help

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nevermind, it is obviously not necessarily orbital angular momentum so that works..

Last edited: Apr 4, 2009