2004/03/31 by Ujjaini Alam, Varun Sahni, A. A. Starobinsky +1 · 8 citations
Physics and Astronomy · #Acceleration #CMB cold spot #Cosmic background radiation #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Dark energy #Epoch (astronomy) #Gamma-ray bursts and supernovae #Particle physics theoretical and experimental studies #Supernova #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1088/1475-7516/2004/06/008
published as JCAP 0406 (2004) 008 · 16 pages, 8 figures. Discussions enhanced, new references added. Matches version published in JCAP
openalex publication_date 2004/06/17 · arxiv created 2004/06/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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 Ω 0m 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 w 0 ≲ −1 at the present epoch and the transition from deceleration to acceleration occurs at z T = 0.39 ± 0.03. However, DE evolution becomes weaker if the ΛCDM based CMB results Ω 0m = 0.27 ± 0.04, h = 0.71 ± 0.06 are incorporated in the analysis. In this case, z T = 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.