Cosmological model discrimination from weak lensing data

S. Pires, J. L. Starck, A. Amara, A. Réfrégier, R. Teyssier

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations


Weak gravitational lensing provides a unique way of mapping directly the dark matter in the Universe. The majority of lensing analyses use the two-point statistics of the cosmic shear field to constrain the cosmological model, a method that is affected by degeneracies, such as that between σ8 and Ωm which are respectively the rms of the mass fluctuations on a scale of 8Mpc/h and the matter density parameter, both at z=0. However, the two-point statistics only measure the Gaussian properties of the field, and the weak lensing field is non-Gaussian. It has been shown that the estimation of non-Gaussian statistics for weak lensing data can improve the constraints on cosmological parameters. In this paper, we systematically compare a wide range of non-Gaussian estimators to determine which one provides tighter constraints on the cosmological parameters. These statistical methods include skewness, kurtosis, and the higher criticism test, in several sparse representations such as wavelet and curvelet; as well as the bispectrum, peak counting, and a newly introduced statistic called wavelet peak counting (WPC). Comparisons based on sparse representations indicate that the wavelet transform is the most sensitive to non-Gaussian cosmological structures. It also appears that the most helpful statistic for non-Gaussian characterization in weak lensing mass maps is the WPC. Finally, we show that the σ8m degeneracy could be even better broken if the WPC estimation is performed on weak lensing mass maps filtered by the wavelet method, MRLens.

Original languageEnglish (US)
Title of host publicationInvisible Universe International Conference
Number of pages10
StatePublished - 2010
Externally publishedYes
EventInvisible Universe International Conference - Paris, France
Duration: Jun 29 2009Jul 3 2009

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


ConferenceInvisible Universe International Conference

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


  • Cosmology: Weak Lensing
  • Data Analysis
  • Methods : Satistics


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