Low-l anomalies of the microwave sky

The cosmic microwave background radiation allows us to probe the largest scales of the Universe at very high precision. Fundamental to modern cosmology is the cosmological principle, which is consequence of the inflationary hypothesis. Testing the statistical isotropy of the foreground-cleaned microwave sky at the largest angular scales reveals unexpected correlations of the microwave radiation with the motion and orientation of the solar system. The evidence and consequences are discussed. (author)