Year: 2004
Type: article
Abstract: The low quadrupole of the cosmic microwave background (CMB), measured by the Cosmic Background Explorer ( COBE ) and confirmed by the Wilkinson Microwave Anisotropy Probe ( WMAP ), has generated much discussion recently. We point out that the well-known correlation between temperature and polarization anisotropies of the CMB further constrains the low-multipole anisotropy data. This correlation originates from the fact that the low-multipole polarization signal is sourced by the CMB quadrupole as seen by free electrons during the relatively recent cosmic history. Consequently, the large-angle temperature anisotropy data make restrictive predictions for the large-angle polarization anisotropy, which depend primarily on the optical depth for electron scattering after cosmological recombination, τ. We show that if current cosmological models for the generation of large-angle anisotropy are correct and the COBE / WMAP data are not significantly contaminated by non-CMB signals, then the observed C amplitude on the largest scales is discrepant at the ~99.8% level with the observed C for the concordant ΛCDM model with τ = 0.10. Using τ = 0.17, the preferred WMAP model-independent value, the discrepancy is at the level of 98.5%.
Source: The Astrophysical Journal
DOI: 10.1086/422496
Authors: Olivier Dore, Gilbert P. Holder, Abraham Loeb
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2012859170