Talk:9-j symbol

Asymptotics

I would like to add a section discussing the asymptotics of the 9-j symbol. This talk section can be used to discuss and improve the proposed asymptotics section on the main page.

These asymptotics have played a role in the study of quantum gravity and have also played a role in atomic physics and the study of symmetry factors in group theoretical calculations for particle physics. There are also asymptotics sections on the 3-j and 6-j symbol pages. — Preceding unsigned comment added by 78.248.106.53 (talk) 20:42, 6 December 2012 (UTC)

12-j and 15-j

There is a way of generalizing from here, to create the higher-j symbols. It would be really really spliffy if this article supplied that generalization. Yes, these do actually show up in calculation. The 12-j has been published in a few obscure books, the 15-j I think has not, but it does occur in the calculation of the rotational microwave spectrum of the highly unstable HO₂ molecule in the upper atmosphere. This many j's are needed because the spin-1/2 of the electron couples to the angular momentum of the molecule, and it really does cause one emission line to be twice as strong as another.linas (talk) 05:39, 25 August 2012 (UTC)