The amplitude of mass fluctuations in the Universe
Year: 1993
Type: article
Abstract: We investigate how the rms linear fluctuation in the mass distribution on scales of 8 h–1 Mpc1 (denoted by σ8) is constrained by the masses and abundances of rich clusters of galaxies. The derived value of σ8 is almost independent of the shape of the fluctuation spectrum, but depends strongly on the cosmological density parameter. We find σ8 ≈ 0.52–0.62 for a critical density universe, and σ8 ≈ 1.25–1.58 for a spatially flat universe with Ω = 0.2. Our results conflict with the high amplitude inferred for an Ω = 1 cold dark matter universe from the COBE anisotropy measurements and advocated on other grounds by Couchman & Carlberg. However, our estimates of σ8 are consistent with alternative models which provide a good fit to the observed shape of galaxy correlations on scales up to 50 h–1 Mpc and match on to the COBE results on larger scales.
Authors: S. D. M. White, G. Efstathiou, C. S. Frenk
Institutions: University of Oxford, Durham University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2074005806