Talk:Minimal coupling

Is this true? I think one gets higher multipole moments from the minimal coupling principle. Because one does a dipole-approximation to get the "E times r" or "A times p" hamiltonian out of the minimal-coupling hamiltonian. I understood that minimal accounts for the most simple introduction of the interaction which yields an gauge invariant hamiltonian. --31.18.25.138 (talk) 19:21, 23 December 2011 (UTC)