The integrated Sachs-Wolfe imprints of cosmic superstructures: a problem for Λ\LambdaCDM

Sep, 2011
9 pages
Published in:
  • JCAP 06 (2012) 042
e-Print:

Citations per year

20112015201920232025024681012
Abstract: (arXiv)
A crucial diagnostic of the \Lambda CDM cosmological model is the integrated Sachs-Wolfe (ISW) effect of large-scale structure on the cosmic microwave background (CMB). The ISW imprint of superstructures of size \sim100\/h^{-1} Mpc at redshift z0.5z\sim0.5 has been detected with >4σ>4\sigma significance, however it has been noted that the signal is much larger than expected. We revisit the calculation using linear theory predictions in \Lambda CDM cosmology for the number density of superstructures and their radial density profile, and take possible selection effects into account. While our expected signal is larger than previous estimates, it is still inconsistent by >3σ>3\sigma with the observation. If the observed signal is indeed due to the ISW effect then huge, extremely underdense voids are far more common in the observed universe than predicted by \Lambda CDM.
Note:
  • 3 figures. v3: minor additions for clearer explanations, conclusions unchanged. Version to be published in JCAP
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