Scalar electromagnetics is an as yet incomplete unified field theory which studies the behavior of vector sum zero electromagnetic systems. Natural Scalar Potentials. For example, white noise. Artificial Scalar potentials have deterministic substructures. The quantum vacuum is a natural scalar potential.
Good definitions exist in textbooks.
Stress on spacetime. The intensity of the natural scalar potential of the quantum vacuum, or any ordering of the virtual particle flux of the quantum vacuum. Order in and of itself it not implied, as in a natural scalar potential. This process is taken from standard quantum mechanics, and is described in textbooks. See exophoton emission.