For some electrostatic potentials, such as that represented by a sufficiently deep well, the Pauli-Weisskopf wave equation has complex frequencies. It is shown that when this happens the quantized field Hamiltonian can no longer be diagonalized. Some points of similarity and difference between this theory and the Dirac positron theory are discussed.

• Received 18 December 1939

DOI:https://doi.org/10.1103/PhysRev.57.315