Peculiar velocities and microwave background anisotropies from cosmic strings

Using an analytic model, we show that the predictions of the cosmic string model for the peculiar velocities and the microwave background (MBR) anisotropy depend on similar combinations of string evolution parameters. Normalizing from the COBE detection of MBR anisotropy, and for certain reasonable values of string network evolution parameters, we find that the magnitude of predicted velocity flows is in good agreement with observations on small scales but is inconsistent with observations on large scales (> 50 h^-1 Mpc). The cosmic Mach number obtained from the cosmic string scenario is found to depend on a single network evolution parameter and is consistent with observations on scales 5 h^-1 Mpc to 20 h^-1 Mpc.