I am writing a program for computing the Wigner d-matrices and ran into an apparent contradiction:
Specifically computing d^1/2_{-1/2,1/2}
According to Edmonds, p.59, 4.1.27 this is given by
(-1)**[1/2-(-1/2)][1!/(1! 0!)]**{1/2} sin(b/2)=-sin(b/2)
Now for d^{1/2}_{1/2,-1/2}
From...