Einstein-Cartan cosmology and the CMB anisotropies

TL;DR

This paper develops linear scalar perturbation equations within Einstein-Cartan cosmology, incorporating torsion effects, to improve understanding of large-scale structure evolution and CMB anisotropies.

Contribution

It derives the first comprehensive set of perturbation equations for Einstein-Cartan gravity applicable to numerical simulations of cosmic structures.

Findings

Equations formulated in conformal Newtonian and synchronous gauges

Framework suitable for N-body simulations including torsion effects

Addresses limitations of standard cosmological models by incorporating torsion

Abstract

We derive linear scalar perturbation equations for Einstein-Cartan field equations of Weyssenhoff fluid, as well as for the corresponding perturbations of Bianchi identity and geodesic equations. The equations are given in both conformal Newtonian and synchronous gauges. They are suitable for numerical implementation when precise evolution of torsion and its perturbation will be extracted from N-body cosmic simulations of the large scale structures in the Universe. A rising number of problems of the concordance cosmological model forces us to include the rotational degrees of freedom realized through torsion in the Einstein-Cartan gravity.