Universe opacity and CMB

TL;DR

This paper proposes a model where the CMB is explained as thermal radiation from intergalactic dust, suggesting the Universe's opacity increases at high redshifts and can account for observed CMB features without a Big Bang origin.

Contribution

It introduces a revived cosmological model where intergalactic dust radiation explains the CMB, challenging the traditional Big Bang interpretation and matching observational data.

Findings

Intergalactic dust temperature predicted as 2.776 K, close to observed CMB temperature.

Universe's opacity increases significantly at redshifts z > 2-3.

CMB fluctuations and polarization anomalies explained by dust and magnetic fields.

Abstract

A cosmological model, in which the cosmic microwave background (CMB) is a thermal radiation of intergalactic dust instead of a relic radiation of the Big Bang, is revived and revisited. The model suggests that a virtually transparent local Universe becomes considerably opaque at redshifts $z > 2-3$. Such opacity is hardly to be detected in the Type Ia supernova data, but confirmed using quasar data. The opacity steeply increases with redshift because of a high proper density of intergalactic dust in the previous epochs. The temperature of intergalactic dust increases as $(1+z)$ and exactly compensates the change of wavelengths due to redshift, so that the dust radiation looks apparently like the radiation of the blackbody with a single temperature. The predicted dust temperature is $T^{D} = 2.776 \, \mathrm{K}$, which differs from the CMB temperature by 1.9\% only, and the predicted ratio between the total CMB and EBL intensities is 13.4 which is close to 12.5 obtained from observations. The CMB temperature fluctuations are caused by EBL fluctuations produced by galaxy clusters and voids in the Universe. The polarization anomalies of the CMB correlated with temperature anisotropies are caused by the polarized thermal emission of needle-shaped conducting dust grains aligned by large-scale magnetic fields around clusters and voids. A strong decline of the luminosity density for $z > 4$ is interpreted as the result of high opacity of the Universe rather than of a decline of the global stellar mass density at high redshifts.