We consider the most general case of the quantization of angular momentum in theN-dimensional space. We show that a hydrogen atom, when viewed in anN-dimensional, multiply connected space, the angular momentum must be ((N−1)/2)-integral.
In the Aharonov-Casher effect, the neutron exerts a non-vanishing force on a static line charge (a charged wire). The reaction of this force is the time rate of change of the electromagnetic momentum.