2006/11/30 by Kyu-Hyun Chae
Physics and Astronomy · #Astronomy and Astrophysical Research #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark matter #Equation of state #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Lambda-CDM model #Velocity dispersion #Weak gravitational lensing #astro-ph
paper · pdf · doi:10.1086/516569
ApJL, accepted (results and presentations revised; conclusions unchanged)
arxiv created 2007/02/22 · openalex publication_date 2007/03/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We improve strong lensing constraints on cosmological parameters in light of the new measurement of the velocity dispersion function of early-type galaxies based on the SDSS DR5 data and recent semianalytical modeling of galaxy formation. Using both the number statistics of the CLASS statistical sample and the image separation distribution of the CLASS and the PANELS radio-selected lenses, we find the cosmological matter density to be Ω m , 0 = 0.25 (68% CL) assuming evolutions of galaxies predicted by a semianalytical model of galaxy formation and Ω m , 0 = 0.26 assuming no evolution of galaxies for a flat cosmology with an Einstein cosmological constant. For a flat cosmology with a generalized dark energy, we find the nonevolving dark energy equation of state w x < -1.2 ( w x < -0.5) at the 68% CL (95% CL).