Talk:Clebsch-Gordan coefficients

From Wikipedia, I changed the lead, added equation for explicit expression (plus discussion) and one special case.--Paul Wormer 03:45, 22 August 2007 (CDT)

Confusement

In the original WP text the i in j _i could stand for x, y, or z, or for "particle number" 1 or 2. In some situations this was confusing, so I introduced x, y and z.--Paul Wormer 07:32, 7 October 2007 (CDT)

Notation of eigenstates

Is there a difference between the states $|(j_{1}j_{2})JM\rangle$ and $|JM\rangle$? I guess not, because the latter notation appears in the orthogonality relation

$\langle JM|J'M'\rangle =\delta _{J\,J'}\delta _{M\,M'}$

without any comment. I find it rather confusing that both notations appear in the definition

$|(j_{1}j_{2})JM\rangle =\sum _{m_{1}=-j_{1}}^{j_{1}}\sum _{m_{2}=-j_{2}}^{j_{2}}|j_{1}m_{1}\rangle |j_{2}m_{2}\rangle \langle j_{1}m_{1}j_{2}m_{2}|JM\rangle$

for the CG coeffs. -- Jitse Niesen 06:37, 30 July 2008 (CDT)

Incidentally, the book we used when learning quantum mechanics (Quantum Physics by Stephen Gasiorowicz) calls them Wigner coefficients; is it just a strange book or is that name really used or are Wigner coefficients something subtly different? -- Jitse Niesen 06:47, 30 July 2008 (CDT)

And another question: the edit history shows that the from-wp flag suddenly disappears. Was this done on purpose? -- Jitse Niesen 07:11, 30 July 2008 (CDT)