COSMIC-RAYS AND COSMOLOGICAL MICROWAVE BACKGROUND FLUCTUATIONS

One of the most important topics in modern cosmology concerns the search for anisotropies in the cosmic microwave background radiation. Searches for these fluctuations have been made in the field of radio astronomy, and tentative claims have been made, specifically at a frequency near to 10 GHz, for fluctuations on a scale of 8-degrees. However, the Galactic synchrotron radiation can mimic or mask a cosmological signal, and the present work examines the extent to which the fluctuations in this local component, a component due to cosmic rays, are understood. We conclude that at 10 GHz, although the observed fluctuations are of similar magnitude to those predicted for Galactic synchrotron radiation the actual temperature profiles do not agree. Thus, the nature of the detected fluctuations is not understood, although what can be stated is that there is no evidence to prove the existence of cosmic microwave background anisotropies. A prognosis is made for future searches for CMB fluctuations.