2006/08/09 by G. L. Li, S. Mao, Shude Mao +6 · 4 citations
Physics and Astronomy · #Anisotropy #Astronomy #Astrophysics #Baryon #CMB cold spot #Cold dark matter #Cosmic microwave background #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Physics #Population #Quantum mechanics #Redshift #Weak gravitational lensing #astro-ph
paper · pdf · doi:10.1111/j.1745-3933.2006.00230.x
published as Mon.Not.Roy.Astron.Soc.Lett. 372 (2006) L73-L77 · 6 pages, 4 figures, 1 table, accepted by MNRAS letters
arxiv created 2006/08/09 · openalex publication_date 2006/09/27 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
Abstract We use high-resolution N-body simulations to investigate the optical depth of giant arcs with length-to-width ratios larger than 7.5 and 10 in the ‘standard’Λ cold dark matter (ΛCDM) model with σ8 = 0.9 and Ωm,0 = 0.3 and a model based on three-year Wilkinson Microwave Anisotropy Probe (WMAP) data. We find that, in dark-matter-only simulations, the lensing probability in the three-year WMAP model (with σ8 = 0.74 and Ωm,0 = 0.238) decreases by a factor of ∼6 compared with that in the ‘standard’Λ cold dark matter (ΛCDM) model. The effects of baryonic cooling, star formation and feedbacks are uncertain, but we argue that baryons will only increase the the lensing cross-section by a moderate factor, ∼2. We conclude that the low central value of σ8 and Ωm,0 preferred by the WMAP three-year data may be too low to be compatible with observations if the conventional assumptions of the background source population are correct.