Moss, Scott, Zibin, “No evidence for anomalously low variance circles on the sky”

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). An independent analysis has confirmed such a result. However, properly simulated Gaussian CMB data contain just the sorts of variations claimed by Gurzadyan & Penrose. Hece there is no evidence for pre-Big Bang phenomena, but have simply re-discovered that the CMB contains structure. Let us summarize this new result by Adam Moss, Douglas Scott, James P. Zibin (Department of Physics & Astronomy, University of British Columbia,Vancouver, Canada), “No evidence for anomalously low variance circles on the sky,” ArXiv, 6 Dec 2010.

“Gurzadyan & Penrose (GP10) claimed that the cosmic microwave background (CMB) obtained by the Wilkinson MicrowaveAnisotropy Probe (WMAP) 7-year data release contains statistically unusual circles which are signatures of events which happened before the hot, dense stage in the usual Big Bang theory. There are directions on the sky centred on which are circles of anomalously low variance in the CMB. They specifically looked at circles around particular positions, calculating the variance within annuli of 0.5◦ width, and plotting this variance as a function of radius. They found some positions where there appeared to be concentric rings of suppressed variance. Moss et al. have reproduced such results using random centres instead of the particular positions selected in GP10.

However, Moss et al. show that the evidence claimed fails to be extraordinary; indeed, such low-variance circles are expected to arise, as properly simulated data show (simulated CMB sky with Gaussian random primordial fluctuations). There are annuli which show prominent dips in variance. There are directions around which there are low variance circles, just like in the real data. It is important to point out that even when a low-variance annulus is identified in real or simulated data, that does not imply the presence of a circular feature in the map. The low variance could simply be due to particularly low fluctuations in a segment of the annulus. Indeed, it is straightforward to repeat the above analysis, but searching for low-variance features of shapes other than circular annuli. Looking for low-variance ‘triangular annuli’, i.e. the regions between concentric equilateral triangles of different sizes show similar trends.

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