Bianchi Type VII_h Models and the WMAP 3-year Data

TL;DR

This study re-evaluates Bianchi Type VIIh cosmological models with WMAP 3-year data, confirming previous correlations with CMB anisotropies and demonstrating robustness against noise and foreground residuals.

Contribution

It provides an updated analysis of Bianchi Type VIIh models using newer WMAP data, reaffirming earlier findings and strengthening the evidence for their potential cosmological significance.

Findings

Confirmed correlation between Bianchi models and WMAP 3-year data

Correlation unaffected by noise or foreground residuals

Previous results remain valid with new data

Abstract

Context. A specific example of Bianchi Type VIIh models, i.e. those including universal rotation (vorticity) and differential expansion (shear), has been shown in Jaffe et al. (2005) to correlate unexpectedly with the WMAP first-year data. Aims. We re-assess the signature of this model in the WMAP 3-year data. Methods. The cross-correlation methods are described in Jaffe et al. (2006a). We use the WMAP 3-year data release, including maps for individual years, and perform additional comparisons to assess the influence of both noise and residual foregrounds and eliminate potential non-cosmological sources for the correlation. Results. We confirm that the signal is detected in both the combined 3-year data and the individual yearly sky maps at a level consistent with our original analysis. The significance of the correlation is not affected by either noise or foreground residuals. Conclusions. The results of our previous study are unchanged.