Paul

 

Suggest you study M.W. Evans, "O(3) Electrodynamics," in Modern Nonlinear Optics, Second Edition, Ed. M. W. Evans, Wiley, 2001, Part II, p. 79-267.

 

There you can find everything you wish to find about O(3) EM.

 

Also, by M.W. Evans in the same volume, see "The Link Between The Sachs and O(3) Theories of Electrodynamics," p. 469; and "The Link between the Topological Theory of Ranada and Trueba, the Sachs Theory, and O(3) Electrodynamics," p. 495.

 

Best wishes,
 

Tom Bearden