The case for dynamical dark energy revisited

Alam, Ujjaini ; Sahni, Varun ; Starobinsky, A. A. (2004) The case for dynamical dark energy revisited Journal of Cosmology and Astroparticle Physics, 2004 . 008 _1-008_16. ISSN 1475-7516

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Official URL: http://iopscience.iop.org/1475-7516/2004/06/008

Related URL: http://dx.doi.org/10.1088/1475-7516/2004/06/008

Abstract

We investigate the behaviour of dark energy using the recently released supernova data of Riess et al 2004 and a model independent parametrization for dark energy (DE). We find that, if no priors are imposed on Ω0m and h, DE which evolves with time provides a better fit to the SNe data than ΛCDM. This is also true if we include results from the WMAP CMB data. From a joint analysis of SNe + CMB, the best fit DE model has w0 ≲−1 at the present epoch and the transition from deceleration to acceleration occurs at zT=0.39 ± 0.03. However, DE evolution becomes weaker if the ΩCDM based CMB results Ω0m=0.27 ± 0.04, h=0.71 ± 0.06 are incorporated in the analysis. In this case, zT=0.57 ± 0.07. Our results also show that the extent of DE evolution is sensitive to the manner in which the supernova data is sampled.

Item Type:Article
Source:Copyright of this article belongs to Institute of Physics.
Keywords:Cosmological Constant Experiments; Dark Energy Theory
ID Code:46253
Deposited On:04 Jul 2011 11:13
Last Modified:04 Jul 2011 11:13

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