On the Einstein-Cartan cosmology vs. Planck data

TL;DR

This paper explores how Einstein-Cartan cosmology, incorporating torsion and angular momentum, can address discrepancies in Planck data related to large-scale anisotropy, power spectrum fitting, and peculiar velocities, offering a potential alternative to standard dark energy models.

Contribution

It demonstrates that Einstein-Cartan cosmology with clustered dark matter and torsion effects can explain large-scale anomalies and velocity flows observed in the Universe, providing a novel theoretical framework.

Findings

Einstein-Cartan model accounts for small-large scale discrepancies.

Negative effective density from torsion reduces large-scale power.

Spin densities of neutrinos contribute to isotropy violation.

Abstract

The first comprehensive analyses of Planck data reveal that the cosmological model with dark energy and cold dark matter can satisfactorily explain the essential physical features of the expanding Universe. However, the inability to simultaneously fit large and small scale TT power spectrum, scalar power index smaller than one and the observations of the violation of the isotropy found by few statistical indicators of the CMB, urge theorists to search for explanations. We show that the model of the Einstein-Cartan cosmology with clustered dark matter halos and their corresponding clustered angular momenta coupled to torsion, can account for small scale - large scale discrepancy and larger peculiar velocities (bulk flows) for galaxy clusters. The nonvanishing total angular momentum (torsion) of the Universe enters as a negative effective density term in the Einstein-Cartan equations causing partial cancellation of the mass density. The integrated Sachs-Wolfe contribution of the Einstein-Cartan model is negative, thus it can provide partial cancellation of the large scale power of the TT CMB spectrum. The observed violation of the isotropy appears as a natural ingredient of the Einstein-Cartan model caused by the spin densities of light Majorana neutrinos in the early stage of the evolution of the Universe and bound to the lepton CP violation and matter-antimatter asymmetry.