On Some Noncanonical Relations of Spinors to Scalars and of the Klein-Gordon and Dirac Equations

We discuss various aspects of noncanonical interpretation of the problem of Lorentz invariance for the Dirac equation suggested by A. Zommerfeld in 1951. In its framework, Dirac field is treated as a quartet of scalar fields whereas spinors do not arise in the theory at all. Then we present principal results of one of the authors' 2007 paper, in which scalar Klein-Gordon fields are treated as potentials for the solutions of Dirac equation, and not as an independent field. The Dirac field then manifests itself as a gauge invariant entity.

Lorentz invariance, spinor transformations, gauge invariance, squared Dirac equation