An Uncooperative Universe: Large Scale Anomalies in the CMB
The Cosmic Microwave Background Radiation is our most important source of information about the early universe. Many of its features are in good agreement with the predictions of the so-called standard model of cosmology — the Lambda Cold Dark Matter Inflationary Big Bang Theory. However, the large-angle fluctuations of the microwave background are uncooperative with “the program” — they continue to exhibit several statistically significant anomalies. On the one hand, if we look at the whole sky the lowest multipoles seem to be correlated both with each other and with the geometry of the solar system. On the other hand, when we look just at the part of the sky that we most trust – the part outside the galactic plane – there is a dramatic lack of large angle correlations. So much so that it challenges basic predictions of the standard model. These anomalies either reflect fundamental new physics of great importance, or our remarkable ability as humans to see patterns where there are none. I will discuss how we might begin to test which of these is the case, even without a model for the anomalies.