How Anisotropic is our Universe? by Bunn, E, Ferreira, P, Silk, J

“…We perform a statistical analysis in which the four-year data from the Cosmic Background Explorer satellite is searched for the specific anisotropy patterns predicted by these models and thereby set definitive upper limits on the amount of shear, $(\sigma/H)_0$ and vorticity, $(\omega/H)_0$, which are orders of magnitude stronger than previous constraints. …”

Constraints on a Primordial Magnetic Field by Barrow, J, Ferreira, P, Silk, J

“…Our limit is derived from a statistical analysis of the 4-year Cosmic Background Explorer data for anisotropy patterns characteristic of homogeneous anisotropy averaged over all possible sky orientations with respect to the COBE receiver. …”

A Bayesian estimate of the skewness of the Cosmic Microwave Background by Contaldi, C, Ferreira, P, Magueijo, J, Gorski, K

“…The formalism is then applied to estimate the skewness of the publicly available 4 year Cosmic Background Explorer (COBE) Differential Microwave Radiometer data. …”