CFHTLenS: cosmological constraints from a combination of cosmic shear two-point and three-point correlations

Liping Fu, Martin Kilbinger, Thomas Erben, Catherine Heymans, Hendrik Hildebrandt, Henk Hoekstra, Thomas D. Kitching, Yannick Mellier, Lance Miller, Elisabetta Semboloni, Patrick Simon, Ludovic Van Waerbeke, Jean Coupon, Joachim Harnois-Deraps, Michael J. Hudson, Konrad Kuijken, Barnaby Rowe, Tim Schrabback, Sanaz Vafaei, Malin Velander

Research output: Contribution to journalArticlepeer-review

Abstract

Higher order, non-Gaussian aspects of the large-scale structure carry valuable information on structure formation and cosmology, which is complementary to second-order statistics. In this work, we measure second- and third-order weak-lensing aperture-mass moments from the Canada-France-Hawaii Lensing Survey (CFHTLenS) and combine those with cosmic microwave background (CMB) anisotropy probes. The third moment is measured with a significance of 2 sigma. The combined constraint on I (8) pound = sigma(8)(Omega(m)/0.27)(alpha) is improved by 10 per cent, in comparison to the second-order only, and the allowed ranges for Omega(m) and sigma(8) are substantially reduced. Including general triangles of the lensing bispectrum yields tighter constraints compared to probing mainly equilateral triangles. Second- and third-order CFHTLenS lensing measurements improve Planck CMB constraints on Omega(m) and sigma(8) by 26 per cent for flat I > cold dark matter. For a model with free curvature, the joint CFHTLenS-Planck result is Omega(m) = 0.28 +/- 0.02 (68 per cent confidence), which is an improvement of 43 per cent compared to Planck alone. We test how our results are potentially subject to three astrophysical sources of contamination: source-lens clustering, the intrinsic alignment of galaxy shapes, and baryonic effects. We explore future limitations of the cosmological use of third-order weak lensing, such as the non-linear model and the Gaussianity of the likelihood function.

Original languageEnglish
Pages (from-to)2725-2743
Number of pages19
JournalMonthly Notices of the Royal Astronomical Society
Volume441
Issue number3
DOIs
Publication statusPublished - 1 Jul 2014

Keywords

  • methods: statistical
  • cosmological parameters
  • MATTER POWER SPECTRUM
  • WEAK-LENSING SURVEYS
  • APERTURE MASS STATISTICS
  • PRECISION COSMOLOGY
  • COVARIANCE-MATRIX
  • NONLINEAR EVOLUTION
  • SPIN-2 FIELDS
  • B-MODES
  • BISPECTRUM
  • TOMOGRAPHY

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