# Talk:6-j symbol

WikiProject Mathematics (Rated Start-class, Low-priority)
This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of Mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Mathematics rating:
 Start Class
 Low Priority
Field: Applied mathematics

## Asymptotics

I would like to add a section discussing the asymptotics of the 6-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 large role in the study of quantum gravity and were used in Ponzano and Regge's original construction of a state sum model for quantum gravity. The asymptotics have also played a role in atomic physics and the study of symmetry factors in group theoretical calculations for particle physics. There is also an asymptotics section on the 3-j symbol page.

added by 71.38.219.188 (talk) 19:12, 10 September 2012 (UTC)

## Orthogonality

I added a section for the main orthogonality relation, since it is a useful result and very similar to the orthogonality for the 9-j symbols which is already given on the 9-j page. I'm not sure about the notation \Delta(i,j,k) for the triangle inequality though; I used this notation for consistency with the existing notation, but I don't like it; usually \Delta(i,j,k) is used for the triangle coefficient, which is quite different but confusing because that coefficient also arises in the definition of the 6-j symbol. http://mathworld.wolfram.com/TriangleCoefficient.html The 9-j symbol page uses the notation {i,j,k}. Perhaps that should be used here too? —Preceding unsigned comment added by 130.102.0.171 (talk) 08:11, 19 February 2008 (UTC)