Lorentz-covariant quantum transport and the origin of dark energy

A possible explanation for the enigma of dark energy, responsible for about 76 % of the mass-energy of the universe, is obtained by requiring only that the rigorous continuity equation (the Boltzmann transport equation) for quanta propagating through space should have the form of a Lorentz-covariant and dispersion-free wave equation. This requirement implies (i) properties of space-time which an observer would describe as uniform expansion in agreement with Hubble's law, and (ii) that the quantum transport behaves like in a multiplicative medium with multiplication factor = 2. This inherent, essentially explosive multiplicity of vacuum, thus caused by the requirement of Lorentz-covariance, is suggested as a potential origin of dark energy. In addition, it is shown (iii) that this requirement of Lorentz-covariant quantum transport leads to an apparent accelerated expansion of the universe. In addition to the updated manuscript for Phys. Scr., the arXiv file also contains a discussion of about a dozen Frequently Asked Questions from readers. Further questions not adequately dealt with in the existing FAQ are welcome.