Correlating anomalies of the microwave sky

Rakic A, Schwarz D. Correlating anomalies of the microwave sky. PHYSICAL REVIEW D. 2007;75(10): 103002.At the largest angular scales the presence of a number of unexpected features has been confirmed by the latest measurements of the cosmic microwave background (CMB). Among them are the anomalous alignment of the quadrupole and octopole with each other as well as the stubborn lack of angular correlation on scales > 60 degrees. We search for correlations between these two phenomena and demonstrate their absence. A Monte Carlo likelihood analysis confirms previous studies and shows that the joint likelihood of both anomalies is incompatible with the best-fit Lambda cold dark matter model at > 99.95% C.L. Extending also to higher multipoles, a common special direction (the "Axis of Evil") has been identified. In the search for an explanation of the anomalies, several studies invoke effects that exhibit an axial symmetry. We find that this interpretation of the "Axis of Evil" is inconsistent with three-year data from the Wilkinson Microwave Anisotropy Probe (WMAP). The data require a preferred plane, whereupon the axis is just the normal direction. Rotational symmetry within that plane is ruled out at high confidence