Physics of Photon Diffusion for Active Sources

Understanding the implications of active sources models, such as topological defects, on the cosmic microwave background is very exciting area of research, since accurate measurements of the CMB over a wide range of scales will soon be available, enabling us to constrain or rule out whole classes of theories, with profound implications for our understanding of physics at high energies. Here, we present a summary of a study of a particular aspect of this subject : the effects of photon diffusion or ‘Silk damping’ . We will extend previous work on passive 2 and active 3,4 theories. A more thorough discussion of this subject is currently in press .