Photon wave function and the electromagnetic vacuum

<p>The association of the density of states theory to the vector potential quantization of the electromagnetic field leads naturally to the definition of the photon quantization volume, ascribing an intrinsic physical geometrical property to a single photon. Photons are not point particles and constitute a particular case in particles standard model. Based upon the vector potential with quantized amplitude, we define a photon wave function representing an amplitude probability for the photon localization normalized with respect to the photon quantization volume. In addition, the established photon wave function satisfies Maxwell's propagation equation and Schrödinger's equation with the relativistic massless particle Hamiltonian as well as a Schrödinger-like equation for the vector potential.&nbsp;</p><p>The electromagnetic vacuum derives straightforward from the photon vector potential function and has both classical and quantum representations. It permits to remedy to the zero-point energy shortcomings and singularities in quantum electrodynamics. Finally, the photon wave function is naturally related to the electromagnetic vacuum states putting the basis for understanding entanglement. &nbsp;&nbsp;</p>