2013/03/31 by C. J. Copi, Craig J. Copi, Dragan Huterer +5 · 40 citations
Physics and Astronomy · #Anisotropy #Astrophysics #Cosmic background radiation #Cosmic microwave background #Cosmic variance #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Physics #Polarization (electrochemistry) #Quantum mechanics #Statistic #Statistical physics #Statistics #Universe #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stt1287
published in Monthly Notices of the Royal Astronomical Society 434(4), 3590-3596 (Oxford University Press) · 7 pages; 6 figures Updated to be consistent with accepted version. Main change is improved discussion of how the constrained realizations are generated
arxiv created 2013/07/24 · openalex publication_date 2013/08/01 · arxiv updated 2015/06/15 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The anomalous lack of large-angle temperature correlations has been a surprising feature of the cosmic microwave background (CMB) since first observed by COBE-DMR and subsequently confirmed and strengthened by the Wilkinson Microwave Anisotropy Probe. This anomaly may point to the need for modifications of the standard model of cosmology or may indicate that our Universe is a rare statistical fluctuation within that model. Further observations of the temperature auto-correlation function will not elucidate the issue; sufficiently high-precision statistical observations already exist. Instead, alternative probes are required. In this work, we explore the expectations for forthcoming polarization observations. We define a prescription to test the hypothesis that the large-angle CMB temperature perturbations in our Universe represent a rare statistical fluctuation within the standard cosmological model. These tests are based on the temperature-Q Stokes parameter correlation. Unfortunately, these tests cannot be expected to be definitive. However, we do show that if this TQ-correlation is observed to be sufficiently large over an appropriately chosen angular range, then the hypothesis can be rejected at a high confidence level. We quantify these statements and optimize the statistics we have constructed to apply to the anticipated polarization data. We find that we can construct a statistic that has a 25 per cent chance of excluding the hypothesis that we live in a rare realization of Λ cold dark matter at the 99.9 per cent confidence level.