Are There Echoes From The Pre-Big-Bang Universe? A Search for Low-Variance Circles in the Cosmic Microwave Background Sky

Hajian 2011: with realistic anisotropic noise, all three circle families are unremarkable

what the source states

"We reassess the statistical significance of those circles by comparing with Monte Carlo simulations of the CMB sky with realistic modeling of the anisotropic noise in WMAP data. We find that the circles are not anomalous and that all three groups are consistent at 3sigma level with a Gaussian CMB sky as predicted by inflationary cosmology model."

what we infer

Closes the loophole that the earlier critiques might have mismodeled WMAP's spatially varying noise — the one technical objection the proponents' first response raised that a better simulation could answer. Three independent groups now reach the same verdict by different routes.

limitations

• Tests the three specific circle families of the founding paper, not every later variant of the claim.