High-z Constraints on the Cosmic String Models with Hot Dark Matter

Abstract

The number densities of quasars and high-redshift galaxies strictly constrain theories of large-scale structure formation. We compute the comoving 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 inflationary hot dark matter theory. We also show that non-Gaussian initial conditions contribute to the number density, and because of this the abundance of objects is higher than expected by the conventional Gaussian Press-Schechter analysis. The cosmic string model with hot dark matter is consistent with the high-redshift observations. However, there might be problems with large-scale structure formation when the power spectrum of strings is compared with the three-dimensional APM spectrum.