Large Angular Scale Anisotropy in Cosmic Microwave Background Induced by Cosmic Strings

We simulate the anisotropy in the cosmic microwave background (CMB) induced by cosmic strings. By numerically evolving a network of cosmic strings we generate full-sky CMB temperature anisotropy maps. Based on 192 maps, we compute the anisotropy power spectrum for multipole moments ≤20. By comparing with the observed temperature anisotropy, we set the normalization for the cosmic string mass per unit length μ, obtaining Gμ/c²0ex0ex=0ex0ex1.05_-0.20+0.35×10^-6, which is consistent with all other observational constraints on cosmic strings. We demonstrate that the anisotropy pattern is consistent with a Gaussian random field on large angular scales.