Revisiting Friedmann-like cosmology with torsion: newest constraints from high-redshift observations

TL;DR

This study uses high-redshift quasar and baryon acoustic oscillation data to constrain Einstein-Cartan cosmology with torsion, finding strong support for torsion plus cosmological constant models and consistency with Planck 2018 results.

Contribution

It provides the first comprehensive constraints on torsion in Einstein-Cartan cosmology using high-redshift observations, extending the analysis to early universe data.

Findings

Torsion plus cosmological constant model is strongly favored by data.

Hubble constant aligns with Planck 2018 CMB results.

Results are compatible with zero spatial curvature.

Abstract

As one of the possible extensions of Einstein's General Theory of Relativity, it has been recently suggested that the presence of spacetime torsion could solve problems of the very early and the late-time universe undergoing accelerating phases. In this paper, we use the latest observations of high-redshift data, coming from multiple measurements of quasars and baryon acoustic oscillations, to phenomenologically constrain such cosmological model in the framework of Einstein-Cartan (EC) endowed with spacetime torsion. Such newly compiled quasar datasets in the cosmological analysis is crucial to this aim, since it will extend the Hubble diagram to high-redshift range in which predictions from different cosmologies can be distinguished. Our results show that out of all the candidate models, the torsion plus cosmological constant model is strongly favoured by the current high-redshift data, where torsion itself would be expected to yield the current cosmic acceleration. Specially, in the framework of Friedmann-like cosmology with torsion, the determined Hubble constant is in very good agreement with that derived from the Planck 2018 CMB results. On the other hand, our results are compatible with zero spatial curvature and there is no significant deviation from flat spatial hypersurfaces. Finally, we check the robustness of high-redshift observations by placing constraints on the torsion parameter $\alpha$, which is strongly consistent with other recent works focusing on torsion effect on the primordial helium-4 abundance.