CMB low multipole alignments in the ΛCDM and dipolar models

The dipolar model [1] 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 ℓ alignments and assuming ΛCDM, 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 ΛCDM. We conclude that the dipolar model does not provide a better fit to the data than the ΛCDM.