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arXiv · 1903.04865

Dark sector interaction: a remedy of the tensions between CMB and LSS data

Suresh Kumar·Rafael C. Nunes·Santosh Kumar Yadav
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Abstract

The well-known tensions on the cosmological parameters $H_0$ and $\sigma_8$ within the $\Lambda$CDM cosmology shown by the Planck-CMB and LSS data are possibly due to the systematics in the data or our ignorance of some new physics beyond the $\Lambda$CDM model. In this letter, we focus on the second possibility, and investigate a minimal extension of the $\Lambda$CDM model by allowing a coupling between its dark sector components (dark energy and dark matter). We analyze this scenario with Planck-CMB, KiDS and HST data, and find that the $H_0$ and $\sigma_8$ tensions disappear at 68\% CL. In the joint analyzes with Planck, HST and KiDS data, we find non-zero coupling in the dark sector up to 99\% CL. Thus, we find a strong statistical support from the observational data for an interaction in the dark sector of the Universe while solving the $H_0$ and $\sigma_8$ tensions simultaneously.

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Suresh Kumar, Rafael C. Nunes, Santosh Kumar Yadav. 2019-03-12. Dark sector interaction: a remedy of the tensions between CMB and LSS data. https://doi.org/10.1140/epjc%2Fs10052-019-7087-7

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