English: This is a wave-based view showing the momentum disturbance of a single oscillation in the quantum electrodynamic (QED) field, also known as "a pair of virtual photons" in a particle-based view. These are the source of the photons comprising Hawking radiation.
Here, the 3D QED field is projected onto a 2D plane and the vertical axis represents the vector momentum, p in an absolute (relativistic) sense. The upper and lower bulges represent virtual photons possessing positive and negative relativistic energy, respectively. This oscillation has no spin-angular momentum (polarization), which would appear as a helical twist. The diameter of the oscillation is its wavelength, (lambda), which cannot factor into the energy of oscillations possessing zero net momentum.
A single oscillation in the QED field comprises momentum components that are on average—but by no means always—equal and opposite. Consequently, the average net relativistic mass-energy of these oscillations is zero.
Zero-point energy comprises oscillations in all types of quantum fields and is the subject of ongoing research in theoretical physics. In part, zero-point energy arises from the Heisenberg uncertainty principle's effect on the QED field—vacuum energy—which allows for non-symmetrical virtual photon momenta (asymmetric bulges). Thus, some oscillations in the quantum electrodynamic field possess non-zero net momentum and non-zero net relativistic mass-energy before quickly vanishing. While momentum asymmetries contribute to vacuum energy, they are not required to produce Hawking radiation.
This image was created using Ashlar-Vellum's Cobalt for the 3D model, Adobe's Photoshop for the annotations, and Apple’s Preview for final color corrections.