Confronting the Ellipsoidal Universe to the Planck 2018 Data

Abstract: We compared the Planck 2018 data on the large-scale anisotropies in the cosmic microwave background to the results obtained in the slightly anisotropic ellipsoidal universe. We focused on the quadrupole temperature correlations to better constrain the eccentricity at decoupling and the direction of the symmetry axis. We found that the quadrupole TE and EE temperature correlations in the ellipsoidal universe are still in reasonable agreement with the Planck 2018 data. We suggested that an experimental estimate of the average large-scale polarisation by the Planck Collaboration could confirm or reject the anisotropic universe proposal.