CMB Anisotropy Induced by Cosmic Strings on Angular Scales $>~ 15'$

Abstract

We have computed an estimate of the angular power spectrum of the Cosmic Microwave Background (CMB) induced by cosmic strings on angular scales $>~ 15'$, using a numerical simulation of a cosmic string network; and decomposed this pattern into scalar, vector, and tensor parts. We find no evidence for strong acoustic oscillations in the scalar anisotropy but rather a broad peak. The anisotropies from vector modes dominate except on very small angular scales while the tensor anisotropies are sub-dominant on all angular scales. The anisotropies generated after recombination are even more important than in adiabatic models. We expect that these qualitative features are robust to the varying of cosmological parameters, a study which has not yet been done.