Minimal uncertainty states for rotation and allied groups

The author shows that the measure of angular momentum uncertainty is the invariant ( Delta J)² identical to (J²)-(J)², rather than sums of products like Delta J₁ Delta J₂, and that the critical states which minimise Delta J are eigenstates of maximum weight of J.n. They also determine the critical states for the associated groups E(2), O(2,1), O(4) and E(3), and construct coherent O(3) spin states mod z) which are superpositions of normal spin eigenvectors and which tend to the classical limit as mod z mod to infinity .