Models with a Step-Like Initial Power Spectrum

Abstract.

We investigate the properties of clusters of galaxies in the $\Lambda$CDM models with a steplike initial power spectrum. We examine the mass function, the peculiar velocities and the power spectrum of clusters in models with different values of the density parameter $\Omega_0$, the normalized Hubble constant h and the spectral parameter p, which describes the shape of the initial power spectrum. The results are compared with observations. We find that the power spectrum of clusters is in good agreement with the observed power spectrum of the Abell-ACO clusters, if the spectral parameter p is in the range $\mbox{p = 0.6-0.8}$. The power spectrum and the rms peculiar velocity of clusters are consistent with observations only if $\Omega_0 < 0.4$.