Beyond Λ\Lambda CDM with low and high redshift data: implications for dark energy

Aug 20, 2018
10 pages
Published in:
  • Gen.Rel.Grav. 52 (2020) 2, 15
  • Published: Feb 7, 2020
e-Print:
Report number:
  • IPM/P-2018/064

Citations per year

201820202022202420250510152025
Abstract: (Springer)
Assuming that the Universe at higher redshifts (z4z \sim 4 and beyond) is consistent with Λ\Lambda CDM model as constrained by the Planck measurements, we reanalyze the low redshift cosmological data to reconstruct the Hubble parameter as a function of redshift. This enables us to address the H0H_0 and other tensions between low z observations and high z Planck measurement from CMB. From the reconstructed H(z), we compute the energy density for the “dark energy” sector of the Universe as a function of redshift without assuming a specific model for dark energy. We find that the dark energy density has a minimum for certain redshift range and that the value of dark energy at this minimum ρDEmin{\rho }_{_{\text {DE}}}^{\text {min}} is negative. This behavior can most simply be described by a negative cosmological constant plus an evolving dark energy component. We discuss possible theoretical and observational implications of such a scenario.
Note:
  • v3: 10 pages, 12 .pdf figure, matching the published version
  • Dark energy
  • Low redshift data
  • CMB
  • H0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}H0\mathrm{H}_0\end{document} tension
  • cosmological constant: negative
  • dark energy: density
  • redshift: high
  • redshift: low
  • phantom: crossing
  • energy: density
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