A Mechanism for Charge Quantization
  We analyze a potential that produces background charges which are automatically quantized. This introduces a new mechanism for charge quantization, although so far it has only been implemented for background charges. We show that this same mechanism can also lead to an alternative means of hiding extra dimensions that is analogous to the Kaluza-Klein approach. 
Theodore J. Allen, Costas J. Efthimiou, Donald Spector