Weak lensing predictions at intermediate scales

Ludovic Van Waerbeke, Takashi Hamana, Román Scoccimarro, Stephane Colombi, Francis Bernardeau

    Research output: Contribution to journalArticlepeer-review

    Abstract

    As pointed out in previous studies, the measurement of the skewness of the convergence field κ will be useful in breaking the degeneracy among the cosmological parameters constrained from weak lensing observations. The combination of shot noise and finite survey volume implies that such a measurement is likely to be performed in a range of intermediate scales (0.5 to 20 arcmin) where neither perturbation theory nor the hierarchical ansatz applies. Here we explore the behaviour of the skewness of κ at these intermediate scales, based on results for the non-linear evolution of the mass bispectrum. We combined different ray-tracing simulations to test our predictions, and we find that our calculations describe accurately the transition from the weakly non-linear to the strongly non-linear regime. We show that the single lens-plane approximation remains accurate even in the non-linear regime, and we explicitly calculate the corrections to this approximation. We also discuss the prospects of measuring the skewness in upcoming weak lensing surveys.

    Original languageEnglish (US)
    Pages (from-to)918-926
    Number of pages9
    JournalMonthly Notices of the Royal Astronomical Society
    Volume322
    Issue number4
    DOIs
    StatePublished - Apr 21 2001

    Keywords

    • Gravitational lensing
    • Large-scale structure of Universe

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

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