2004/02/27 by Robert R. Caldwell, Marc Kamionkowski · 3 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1088/1475-7516/2004/09/009
published as JCAP 0409 (2004) 009 · 4 pages, 1 color figure
arxiv created 2004/02/27 · openalex publication_date 2004/09/18 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In general-relativistic cosmological models, the expansion history, matter content, and geometry are closely intertwined. In this brief paper, we clarify the distinction between the effects of geometry and expansion history on the luminosity distance. We show that the cubic correction to the Hubble law, measured recently with high-redshift supernovae, is the first cosmological measurement, apart from the cosmic microwave background, that probes directly the effects of spatial curvature. We illustrate the distinction between geometry and expansion with a toy model for which the supernova results already indicate a curvature radius larger than the Hubble distance.