On the structure of the electron

Usually the electron is described as a mathematical point with charge, mass, spin angular momentum, and electromagnetic field. Because of the unbounded energies this causes mathematical difficulties. These can be avoided by considering a finite radius. For a ''free electron at rest'' a classical relativistic model is presented where an axisymmetric torus models the electron. This configuration ''differentially rotates'' around its axis of symmetry with superluminal speed. (orig.)