AMPLITUDE OF PRIMEVAL FLUCTUATIONS FROM COSMOLOGICAL MASS DENSITY RECONSTRUCTIONS

We use the POTENT reconstruction of the mass density field in the near by universe to estimate the amplitude of the density fluctuation power spectrum for various cosmological models. We find sigma8OMEGA(m)0.6 = 1.3(-0.3)+0.4, almost independently of the power spectrum. This value agrees well with the COBE normalization for the standard cold dark ma tter model, while some alternative models predict an excessive amplitu de compared with COBE. Flat, low OMEGA(m) models and tilted models wit h spectral index n < 0.8 are particularly discordant.