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arXiv · 1503.01611

CMB low multipole alignments in the $\mathbfΛ$CDM and Dipolar models

L. Polastri·A. Gruppuso·P. Natoli
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Abstract

The dipolar model \cite{Gordon:2005ai} has attracted much interest because it may phenomenologically explain the CMB hemispherical power asymmetry found in the WMAP and Planck data. Since such a model explicitly breaks isotropy at large angular scales it is natural to wonder whether it can also explain other CMB directional anomalies. Focusing on the low $\ell$ alignments and assuming $Λ$CDM, we confirm that the quadrupole/octupole and the dipole/quadrupole/octupole alignments are anomalous with a significance up to $99.9\%$ C.L., for both WMAP and Planck data. Moreover, we show for the first time that such features are anomalous also in the dipolar model, roughly at the same level as in $Λ$CDM. We conclude that the dipolar model does not provide a better fit to the data than the $Λ$CDM.

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L. Polastri, A. Gruppuso, P. Natoli. 2015-03-05. CMB low multipole alignments in the $\mathbfΛ$CDM and Dipolar models. https://doi.org/10.1088/1475-7516%2F2015%2F04%2F018

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