Amplitude of Primeval Fluctuations from Cosmological Mass Density Reconstructions

Abstract

We use the POTENT reconstruction of the mass density field in the nearby universe to estimate the amplitude of the density fluctuation power spectrum for various cosmological models. We find sigma_8Ω_m^{0.6}= 1.3^{+0.4}_{-0.3}, almost independently of the power spectrum. This value agrees well with the COBE normalization for the standard CDM model, while some alternative models predict an excessive amplitude compared with COBE. Flat low Ω_m models and tilted models with spectral index n<0.8 are particularly discordant.

10 pages, AAS Latex v3.0, 1 figure and postscript available by anonymous ftp to arcturus.mit.edu, ApJ, in press 1994, preprint MIT-CSR-93-33