The Ellipsoidal Universe in the Planck Satellite Era

Abstract: Recent Planck data confirm that the cosmic microwave background displays the quadru-pole power suppression together with large scale anomalies. Progressing from previous results, that focused on the quadrupole anomaly, we strengthen the proposal that the slightly anisotropic ellipsoidal universe may account for these anomalies. We solved at large scales the Boltzmann equation for the photon distribution functions by taking into account both the effects of the inflation produced primordial scalar perturbations and the anisotropy of the geometry in the ellipsoidal universe. We showed that the low quadrupole temperature correlations allowed us to fix the eccentricity at decoupling, $e_{\rm dec} \, = \, (0.86 \, \pm \, 0.14) \, 10^{-2}$, and to constraint the direction of the symmetry axis. We found that the anisotropy of the geometry of the universe contributes only to the large scale temperature anisotropies without affecting the higher multipoles of the angular power spectrum. Moreover, we showed that the ellipsoidal geometry of the universe induces sizable polarization signal at large scales without invoking the reionization scenario. We explicitly evaluated the quadrupole TE and EE correlations. We found an average large scale polarization $\Delta T_{pol} \, = \, (1.20 \, \pm \, 0.38) \; \mu K $. We point out that great care is needed in the experimental determination of the large-scale polarization correlations since the average temperature polarization could be misinterpreted as foreground emission leading, thereby, to a considerable underestimate of the cosmic microwave background polarization signal.