Models for the Evolution of the Two Point Correlation Function

The spatial two point galaxy correlation function, ξ(r), is, at present, the most useful statistic for comparing theoretical models to observational data. We have derived an expression for the dynamical evolution of ξ for structures arising from Gaussian initial conditions under the assumption that non-linear evolution may be described by the Zel’dovich approximation. The observed angular correlation function of galaxies, ω(θ), may place useful constraints on the spectrum of initial fluctuations on large scales. The angular correlation function due to the growth of structure from Gaussian fluctuations with the Cold Dark Matter spectrum is calculated. It is shown that ωg for the Ω = 1 biassed CDM model exhibits a gentle falloff near the position of the break found by Groth and Peebles in the Shane-Wirtanen catalogue.