Retracted: New aspects of photon propagation in expanding universes

Abstract

Background Modern cosmology assumes that the cosmic microwave background (CMB) radiation is a relict of the much hotter electromagnetic radiation field from the early recombination era of the universe. Its present very low radiation temperature TCMB = 2.735 K thereby is explained by the fact that the cosmic photons in the expanding universe undergo a wavelength stretching according to λ/λ0 = S/S0, where S denotes the scale of the universe. The present-day CMB temperature hence simply expresses the factor by which the universe has grown since the recombination era. Materials and Methods On the basis of well-known facts of Special and General Relativity (SRT and GRT), we reinvestigate the behavior of freely propagating cosmic photons in dynamic Robertson-Walker spacetime geometries and show that in the system of the propagating photon, due to the fact that no time lapses in this proper system, the photon does not change its initial state, that is, its wavelength and energy. We do, however, also show that the global beat of the time changes with the cosmic world time or the cosmic scale S. That means cosmic photons do not change their state, till they are registered by a local detector, that is, a local clock. Results We claim that the energy density of cosmic photons which enters the energy-momentum tensor of Einstein's GRT field equations does not scale like S−4 as assumed in present-day cosmology, but like S−3, that is, identically to the behavior of the energy densities of baryonic or dark matter, meaning that the energy density of photons in the present-day universe cannot be neglected, but counts substantially for the expansion history of the universe. Nevertheless, we show that cosmic photons measured with a present-day detector (local clock) locally will show their cosmological redshift, explaining the present-day CMB Planck spectrum with a Planck temperature of 2.735 K. Conclusions As the energy density of cosmic photons cannot be neglected, their contribution in the GRT energy-momentum tensor is important over all phases of the expansion of the universe. They are thus acting identical to the way how dark matter acts and influences cosmic expansion. This means that the present-day claim for a dark matter contribution in cosmic expansion by Ωdark≃0.23 can be substantially relaxed.