The WMAP team has just released a new set of papers based upon seven years of data from their experiment. For a summary of how this new data has sharpened some of their previous results, see the Cosmological Interpretation paper. They have also gone over claims by many groups to have found deviations from the standard cosmological model in their earlier data sets (for example claims to have found “the unmistakable imprint of another universe” which “points to string theory being on the right track.”) In a paper entitled Are There Cosmic Microwave Background Anomalies, the WMAP team reports:
In most cases we find that claimed anomalies depend on posterior selection of some aspect or subset of the data… We examine several potential or previously claimed anomalies in the sky maps and power spectra, including cold spots, low quadrupole power, quadropole-octupole alignment, hemispherical or dipole power asymmetry, and quadrupole power asymmetry. We conclude that there is no compelling evidence for deviations from the LCDM model
They give a humorous example of the problem that plagues typical claims to have found such anomalies, showing that the CMB sky map clearly contains the initials of Stephen Hawking, “aligned neatly along a line of fixed Galactic latitude.”
Update: For the WMAP team’s summary of its new results for the public, see here.