o..O sounds fascinating :-) I keep thinking about if its trivial or not, there was actually one colleague - a bit of a strange guy - who said that its all long known that JT makes paramagnetism. But I doubt anyone ever looked at the maths behind.
That reminds me in the magnetism peace, thats actually the one which is easiest to state its enough to remind people that paramagnetic susceptibilty is determined by $<\psi_0|\hat{l}_z|\psi_i>$, $0$ ground and $i$ virtual(=excited) state.
Given that, do you see why our systems show paramagnetic susceptibility?
"who said that its all long known that JT makes paramagnetism." Moreover in general its wrong, it only holds for $G$ groups not for $G'$ groups. And that's so to say exactly the gist of the whole thing.
@mercio: "In the case $R$ is the representation of a point group, the anti-symmetric part $Alt^2(R)$ is the representation of the momentum operator." for that we need some explanation.
OK. In any case we need like one defintion E.g. Alt^2(G) =Rot_z, and then that Rot_z is indeed on l_z. I suppose the idea of the current version is to put that to the supp. info. But also in that case we should mention, that this is shown there.
