The Symmetry Underlying Spin and the Dirac Equation
  It is shown, in the context of a recent formulation of elementary particles in terms of, what may be called, a Quantum Mechanical Kerr-Newman metric, that spin is a consequence of a space-time cut off at the Compton wavelength and Compton time scale. On this basis, we deduce the Dirac equation from a simple coordinate transformation. 
B.G. Sidharth