1999/06/30 by James Robinson, James C. Robinson, Eric Gawiser +1 · 1 citation
Physics and Astronomy · #Abundance (ecology) #Astronomy and Astrophysical Research #Astrophysics #Biology #Cluster (spacecraft) #Computer science #Cosmic microwave background #Cosmology #Ecology #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Gaussian #Non-Gaussianity #Physics #Quantum mechanics #Range (aeronautics) #Redshift #Statistical physics #Stellar, planetary, and galactic studies #Universe #astro-ph
paper · pdf · doi:10.1086/308549
published as Astrophys.J. 532 (2000) 1 · Minor revisions to match published ApJ version, 14 pages emulateapj
openalex publication_date 2000/03/20 · arxiv created 2000/05/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We show how observations of the evolution of the galaxy cluster number abundance can be used to constrain primordial non-Gaussianity in the universe. We carry out a maximum likelihood analysis incorporating a number of current data sets and accounting for a wide range of sources of systematic error. Under the assumption of Gaussianity, the current data prefer a universe with matter density Ω m ≃ 0.3 and are inconsistent with Ω m = 1 at the 2 σ level. If we assume Ω m = 1, the predicted degree of cluster evolution is consistent with the data for non-Gaussian models where the primordial fluctuations have at least twice as many peaks of height 3 σ or more as a Gaussian distribution does. These results are robust to almost all sources of systematic error considered: in particular, the Ω m = 1 Gaussian case can only be reconciled with the data if a number of systematic effects conspire to modify the analysis in the right direction. Given an independent measurement of Ω m , the techniques described here represent a powerful tool with which to constrain non-Gaussianity in the primordial universe, independent of specific details of the non-Gaussian physics. We discuss the prospects and strategies for improving the constraints with future observations.