Perhaps the slickest utilization of Cartan's exterior differential forms is the derivation of Maxwell's first pair of equations on a variety without metric and without connection. Maxwell's equations are statements of topology, not geometry. It is also remarkable that the Maxwell equations are the first four elements of a nested set in any number of dimensions!

The second pair of Maxwell equations take a little more doing. The fashionable way is to claim that the seond Maxell pair is the "dual" of the first Maxwell pair. Such self dual constraints and limitations are the basis of Yang Mill type theories. Such theories do not explain optical activity or the Faraday effect. See "Parity and Time-reversal Symmetry Breaking..."

The first Maxwell pair has to do with forces, the second Maxwell pair has to do with sources. The first Maxwell pair is on a non-compact symplectic manifold. The second Maxwell pair can be on a compact domain.
See also piers97.pdf

	Downloads
	maxwell.pdf 148k	.tex NA	ranada.zip 5k