Information content in the angular power spectrum of weak lensing: wavelet method

Authors

  • Hao-Ran Yu,

    1. Department of Astronomy, Beijing Normal University, Beijing, 100875, China
    2. Canadian Institute for Theoretical Astrophysics, University of Toronto, Ontario, M5S 3H8, Canada
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  • Joachim Harnois-Déraps,

    1. Canadian Institute for Theoretical Astrophysics, University of Toronto, Ontario, M5S 3H8, Canada
    2. Department of Physics, University of Toronto, Ontario, M5S 1A7, Canada
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  • Tong-Jie Zhang,

    Corresponding author
    1. Department of Astronomy, Beijing Normal University, Beijing, 100875, China
    2. Center for High Energy Physics, Peking University, Beijing, 100871, China
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  • Ue-Li Pen

    1. Canadian Institute for Theoretical Astrophysics, University of Toronto, Ontario, M5S 3H8, Canada
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E-mail: tjzhang@bnu.edu.cn

ABSTRACT

We quantify the performance of a non-linear Wiener filter, constructed in wavelet space, at recovering some of the Fisher information that was lost in the weak lensing convergence field. The proposed method consists of a separation of the original field into the sum of a Gaussian and a non-Gaussian contribution. After filtering an ensemble of such fields, which are obtained from N-body simulations, we find that we can recapture about four times more Fisher information, an effect that can potentially improve by a significant amount the constraining power of weak lensing surveys on cosmological parameters, including the dark energy equation of state ω. We compare this performance with that of a logarithmic mapping and find that the wavelet method can recover up to three times more information.

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