Hi! Thanks for pay attention. I am learning spinfoam model through Rovelli's book and other reviews. I don't know how to perform the derivation of the integration:(adsbygoogle = window.adsbygoogle || []).push({});

[tex]\int{dU R^{j1}(U)^{a}_{a'} R^{j2}(U)^{b}_{b'} R^{j3}(U)^{c}_{c'}=v^{abc}v_{a'b'c'}}[/tex]

the integration is over SU(2), the measure dU is Haar measure. And the RHS are two intertwiner between representation j1,j2,and j3.

Can anyone helps me with some clues or just some reference that I can find the answer.

Thanks a lot!!

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# Question in learning spinfoam

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