2003/06/30 by S. W. Allen, R. W. Schmidt, Sarah Bridle +1 · 5 citations
Physics and Astronomy · #Astrophysics #Astrophysics and Cosmic Phenomena #Baryon #Cosmic microwave background #Cosmology and Gravitation Theories #Galaxy #Galaxy cluster #Hubble's law #Neutrino #Neutrino Physics Research #Particle physics #Physics #Redshift #astro-ph #hep-ph
paper · pdf · doi:10.1046/j.1365-2966.2003.07022.x
published as Mon.Not.Roy.Astron.Soc.346:593,2003 · Final version. MNRAS, in press (9 pages, 6 figures, 1 table). Includes small modification to the neutrino mass calculation and comment on quintessence. Conclusions unchanged
arxiv created 2003/08/20 · openalex publication_date 2003/11/19 · arxiv updated 2009/11/30 · openalex created_date 2021/02/01 · openalex updated_date 2026/08/05
We present results from the analysis of cosmic microwave background (CMB), large-scale structure (galaxy redshift survey) and X-ray galaxy cluster (baryon fraction and X-ray luminosity function) data, assuming a geometrically flat cosmological model and allowing for tensor components and a non-negligible neutrino mass. From a combined analysis of all data, assuming three degenerate neutrino species, we measure a contribution of neutrinos to the energy density of the Universe, Ωνh2= 0.0059+0.0033−0.0027 (68 per cent confidence limits), with zero falling on the 99 per cent confidence limit. This corresponds to ∼4 per cent of the total mass density of the Universe and implies a species-summed neutrino mass , or mν∼ 0.2 eV per neutrino. We examine possible sources of systematic uncertainty in the results. Combining the CMB, large-scale structure and cluster baryon fraction data, we measure an amplitude of mass fluctuations on 8 h−1 Mpc scales of σ8= 0.74+0.12−0.07, which is consistent with measurements based on the X-ray luminosity function and other studies of the number density and evolution of galaxy clusters. This value is lower than that obtained when fixing a negligible neutrino mass (σ8= 0.86+0.08−0.07). The combination of CMB, large-scale structure and cluster baryon fraction data also leads to remarkably tight constraints on the Hubble constant, H0= 68.4+2.0−1.4 km s−1 Mpc−1, mean matter density, Ωm= 0.31 ± 0.02, and physical baryon density, Ωbh2= 0.024 ± 0.001, of the Universe.