HIGH-Z CONSTRAINTS ON THE COSMIC-STRING MODELS WITH HOT DARK-MATTER

The number densities of quasars and high-redshift galaxies strictly co nstrain theories of large-scale structure formation. We compute the co moving space densities of these objects with a cosmic string plus hot dark matter model and compare results with observations. We show that the cosmic string model works considerably better than the standard in flationary hot dark matter theory. We also show that non-Gaussian init ial conditions contribute to the number density, and because of this t he abundance of objects is higher than expected by the conventional Ga ussian Press-Schechter analysis. The cosmic string model with hot dark matter is consistent with the high-redshift observations. However, th ere might be problems with large-scale structure formation when the po wer spectrum of strings is compared with the three-dimensional APM spe ctrum.