Source of vacuum electromagnetic zero-point energy

Nature provides us with two alternatives for the origin of electromagnetic zero-point energy (ZPE): existence by fiat as part of the boundary conditions of the universe, or generation by the (quantum-fluctuation) motion of charged particles that constitute matter. A straightforward calculation of the latter possibility has been carried out in which it is assumed that the ZPE spectrum (field distribution) drives particle motion, and that the particle motion in turn generates the ZPE spectrum, in the form of a self-regenerating cosmological feedback cycle. The result is the appropriate frequency-cubed spectral distribution of the correct order of magnitude, thus indicating a dynamic-generation process for the ZPE fields.