Subdegree-Scale Microwave Anisotropies from Cosmic Defects

Abstract

If current ideas about unified field theories are correct, macroscopic cosmic defects may well exist. The observation of such an entity would have enormous significance for our understanding of fundamental physics. This paper points out a novel observable signature of cosmic texture and global monopoles, namely, strong hot spots in the cosmic microwave anisotropy pattern on subdegree scales. This signal should be readily detectable by the next generation of anisotropy mapping experiments. The signature arises from overdensities in the photon-baryon fluid generated by the gravitational attraction of the defects. A rough determination is given for the angular power spectrum of the anisotropy fluctuations for cosmic string, global monopoles, and texture.