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 that 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 nu = 2. This inherent, essentially explosive multiplicity of vacuum, 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.