A search for concentric circles in the 7-year WMAP temperature sky maps

TL;DR

This study independently searches for concentric low-variance circles in WMAP data, verifying previous claims but finding results consistent with the standard LCDM cosmological model, thus challenging earlier assertions of pre-Big Bang activity.

Contribution

The paper provides an independent analysis using chi^2 and matched filters, and shows that the observed structures are consistent with LCDM simulations, contradicting prior claims of significant pre-Big Bang signals.

Findings

Reproduced the ring structures claimed by Gurzadyan and Penrose.

Found larger variance in simulations, aligning WMAP data with LCDM.

Challenged previous evidence for pre-Big Bang activity.

Abstract

In a recent analysis of the 7-year WMAP temperature sky maps, Gurzadyan and Penrose claim to find evidence for violent pre-Big Bang activity in the form of concentric low-variance circles at high statistical significance. In this paper, we perform an independent search for such concentric low-variance circles, employing both chi^2 statistics and matched filters, and compare the results obtained from the 7-year WMAP temperature sky maps with those obtained from LCDM simulations. Our main findings are the following: We do reproduce the claimed ring structures observed in the WMAP data as presented by Gurzadyan and Penrose, thereby verifying their computational procedures. However, the results from our simulations do not agree with those presented by Gurzadyan and Penrose. On the contrary we obtain a substantially larger variance in our simulations, to the extent that the observed WMAP sky maps are fully consistent with the LCDM model as measured by these statistics.