1303.5051 (A. Rassat et al.)
A. Rassat, J. -L. Starck
There is currently a debate over the existence of claimed statistical anomalies in the Cosmic Microwave Background (CMB). Recent work has focussed on comparing different methods for measuring statistical significance, as well as on the impact of masks and secondary anisotropies as potential causes of the anomalies. Following Rassat, Starck & Dupe 2013, we aim to investigate simultaneously the impact of the method used to account for masked regions as well as the impact of the integrated Sachs-Wolfe (ISW) effect. Our aim is to identify trends in CMB data from different years and with different masks treatment, including the latest WMAP9 data. We use the reconstructed ISW field (from Rassat, Starck & Dupe 2013) due to 2 Micron All-Sky Survey (2MASS) and NRAO VLA Sky Survey (NVSS), effectively reconstructing the low-redshift ISW signal out to $z\sim1$. Regions of missing data are accounted for using the sparse inpainting technique described in Starck, Fadili & Rassat 2013, which does not assume the underlying field is either Gaussian or isotropic, but allows for it to be. We focus on two large-scale anomalies, namely the Axis of Evil (AoE) statistic and even/odd mirror parity, both of which search for preferred axes in the Universe. After sparse inpainting and subtraction of the ISW field, we find that there is no longer any AoE or mirror parity anomaly in any of the WMAP renditions. In Rassat, Starck & Dupe 2013, we had also showed that the low quadrupole, quadrupole/octopole alignment and the octopole planarity anomalies also disappeared after subtraction of the ISW effect, showing that there seems to be no reason to believe that there exists any statistical anomalies in the CMB after all.
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http://arxiv.org/abs/1303.5051
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