A spatial-correlation analysis of the cubic 3-torus topology based on the Planck 2013 data

Understand

Spatial correlations of the cubic 3-torus topology are analysed using the Planck 2013 data.

• The spatial-correlation method for detecting multiply connected spaces is based on the fact that positions on the cosmic microwave background (CMB) sky, that are separated by large angular distances, can be spatially much nearer according to a hypothesized topology.
• The comparison of the correlations computed with and without the assumed topology can reveal whether a promising topological candidate is found.
• The level of the expected correlations is estimated by CMB simulations of the cubic 3-torus topology and compared to those obtained from the Planck data.