Institute for Advanced Study Astrophysics Seminar

ABSTRACT: 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. However, the large-angle fluctuations of the microwave background exhibit several statistically significant anomalies compared to the predictions of the standard model. 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 no choice of theoretical powerspectrum can explain it if the alms are, as inflation predicts, Gaussian random statistically isotropic variables of zero mean.