English

Is it time to go beyond $\Lambda$CDM universe?

Cosmology and Nongalactic Astrophysics 2017-06-14 v2 General Relativity and Quantum Cosmology

Abstract

Concordance Λ\LambdaCDM universe is the simplest model that is consistent with a large variety of cosmological observations till date. But few recent observations indicate inconsistencies in Λ\LambdaCDM model. In this paper, we consider the combination of recent SnIa+Bao+Cmb+Growth+H(z)H(z)+H0H_{0} measurements to revisit the constraints on the dark energy evolution using the widely studied CPL parametrisation for the dark energy equation of state. Although the reconstructed behaviour for the dark energy equation of state confirms the inconsistency of Λ\LambdaCDM at 95%95\% confidence level, the reconstructed OmOm diagnostic which is a {\it null test} for Λ\LambdaCDM, still allows the concordance Λ\LambdaCDM behaviour with a lower range of Ωm0\Omega_{m0} than that obtained by Planck-2015. {\it This confirms that Λ\LambdaCDM is still the best choice for the dark energy model}. We also measure the parameter S=σ8Ωm0/0.3=0.728±0.023S = \sigma_{8}\sqrt{\Omega_{m0}/0.3} = 0.728 \pm 0.023 which is consistent with its recent measurement by KiDS survey. The confidence contour in the Ωm0σ8\Omega_{m0}-\sigma_{8} parameter plane is also fully consistent with KiDS survey measurement.

Keywords

Cite

@article{arxiv.1705.07336,
  title  = {Is it time to go beyond $\Lambda$CDM universe?},
  author = {Anto I. Lonappan and Ruchika and Anjan A Sen},
  journal= {arXiv preprint arXiv:1705.07336},
  year   = {2017}
}

Comments

13 pages, LateX style, 1 table, 6 eps figures. New References and figures added. Conclusions remain the same

R2 v1 2026-06-22T19:53:33.193Z