Dark Matter, Cosmic Strings, and Large Scale Structure

Abstract

Although the hypothesis of cold dark matter with a Zeldovich spectrum of primordial Gaussian fluctuations appears to give a picture of galaxy and cluster formation that is in reasonably good agreement with the available observations, there are indications that this model leads to less structure on very large scales than is observed. This paper gives a progress report on our efforts to study the formation of large scale structure in models with either (a) an additional feature in the fluctuation spectrum on large scales, such as can arise in a hybrid model with comparable amounts of baryonic and cold dark matter, or (b) non-Gaussian fluctuations, for example those that arise from cosmic strings. Although we cannot yet tell whether either approach will ultimately be sucessful, our preliminary results confirm that cosmic strings can lead to the sorts of rich cluster correlations that are observed.