Pauli, W. and Weisskopf, V. (1934) The Quantization of the Scalar Relativistic Wave Equation. Helvetica Physica Acta, 7, 709-731. English Translation: Miller, A.I. (1994) Early Quantum Electrodynamics, University Press, Cambridge, 188-205.

has been cited by the following article:

• TITLE: Hamiltonian, Lagrangian and Physical Laws

  AUTHORS: E. Comay

  KEYWORDS: The Correspondence Principle, Constraints on Quantum Theories, the Variational Principle, First Order Quantum Equations, Second Order Quantum Equations

  JOURNAL NAME: Open Access Library Journal, Vol.6 No.7, July 18, 2019

  ABSTRACT: The significance of the correspondence between the classical limit of quantum theories and the laws of classical physics is explained. It is proved that this correspondence yields constraints on acceptable quantum theories. The variational principle is taken as the basis of the analysis. The discussion shows that the first order Dirac equation abides by these constraints, whereas second order quantum equations fail to do that.