TEW book, Section 7.5, where the "flux" idea is first introduced. Emphasis added. Paragraph breaks added.
Picture of Elementary Wave Flux
The waves coming from each slit in Figure 2.4 (Illustration of Wave Interference) begin at the slit and propagate out from there in all directions. This behavior is characteristic of waves propagating in a medium, or along the surface of a body or water in the case of water waves. Elementary waves do not propagate in a medium. They are “stand-alone” objects in their own right.
The elementary wave along a line that a particle might follow moves as a single, independent unit. It might best be described as a “flux” that carries the wave oscillations along with it. The elementary wave previously described as emanating from a detector, or from a point on the screen in the double-slit experiment, and moving out from there in all directions actually consists of an independent flux line along each of the many directions from that detector.
The detector gives the independent fluxes a common phase and marker, so they add up to what looks exactly like a wave propagating in all directions, but the individual fluxes are nonetheless independent. The fluxes move with the velocity of light, c.
Wikipedia: Zero-point energy
In physics, the zero-point energy is the lowest possible energy that a quantum mechanical physical system may have and is the energy of the ground state. The quantum mechanical system that encapsulates this energy is the zero-point field. The concept was first proposed by Albert Einstein and Otto Stern in 1913. The term "zero-point energy" is a calque of the German Nullpunktenergie. All quantum mechanical systems have a zero-point energy. The term arises commonly in reference to the ground state of the quantum harmonic oscillator and its null oscillations.
Zero-point energy is sometimes used as a synonym for the vacuum energy, an amount of energy associated with the vacuum of empty space. In cosmology, the vacuum energy is one possible explanation for the cosmological constant. The variation in zero-point energy as the boundaries of a region of vacuum move leads to the Casimir effect, which is observable in nanoscale devices.
A related term is zero-point field, which is the lowest energy state of a field; i.e. its ground state, which is non-zero.
2 typos fixed but not shown. Subject line changed.
Excerpt from TEW book added.
Common description of term from Wikipedia, added.