Statistics of Peculiar Velocities from Cosmic Strings

Abstract

We calculate the probability distribution of a single component of peculiar velocities due to cosmic strings, smoothed over regions with a radius of several $h^{-1}$ Mpc. The probability distribution is shown to be Gaussian to good accuracy, in agreement with the distribution of peculiar velocities deduced from the 1.9 Jy IRAS redshift survey. Using the normalization of parameters of the cosmic string model from CMB measurements, we show that the rms values for peculiar velocities inferred from IRAS are consistent with the cosmic string model provided that long strings have some small-scale structure.