No evidence for anomalously low variance circles on the sky
  In a recent paper, Gurzadyan & Penrose claim to have found directions on the
sky centred on which are circles of anomalously low variance in the cosmic
microwave background (CMB). These features are presented as evidence for a
particular picture of the very early Universe. We attempted to repeat the
analysis of these authors, and we can indeed confirm that such variations do
exist in the temperature variance for annuli around points in the data.
However, we find that this variation is entirely expected in a sky which
contains the usual CMB anisotropies. In other words, properly simulated
Gaussian CMB data contain just the sorts of variations claimed. Gurzadyan &
Penrose have not found evidence for pre-Big Bang phenomena, but have simply
re-discovered that the CMB contains structure.
