  The anisotropies in the galaxy two-point correlation function measured from
redshift surveys exhibits deviations from the predictions of the linear theory
of redshift space distortion on scales as large 20 Mpc/h where we expect linear
theory to hold in real space. Any attempt at analyzing the anisotropies in the
redshift correlation function and determining the linear distortion parameter
\beta requires these deviations to be correctly modeled and taken into account.
These deviations are usually attributed to galaxy random motions and these are
incorporated in the analysis through a phenomenological model where the linear
redshift correlation is convolved with the random pairwise velocity
distribution function along the line of sight. We show that a substantial part
of the deviations arise from non-linear effects in the mapping from real to
redshift space caused by the coherent flows. Models which incorporate this
effect provide a better fit to N-body results as compared to the
phenomenological model which has only the effect of random motions. We find
that the pairwise velocity dispersion predicted by all the models that we have
considered are in excess of the values determined directly from the N-body
simulations. This indicates a shortcoming in our understanding of the
statistical properties of peculiar velocities and their relation to redshift
distortion.
