Enhancing cosmic shear with the multiscale lensing probability density function

B Giblin*, Yan-Chuan Cai, Joachim Harnois-Deraps

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

We quantify the cosmological constraining power of the ‘lensing probability density function (PDF)’ – the one-point probability density of weak lensing convergence maps – by modelling this statistic numerically with an emulator trained on w cold dark matter cosmic shear simulations. After validating our methods on Gaussian and lognormal fields, we show that ‘multiscale’ PDFs – measured from maps with multiple levels of smoothing – offer considerable gains over two-point statistics, owing to their ability to extract non-Gaussian information: For a mock Stage-III survey, lensing PDFs yield 33 per cent tighter constraints on the clustering parameter S8=σ8Ωm/0.3−−−−−−√ than the two-point shear correlation functions. For Stage-IV surveys, we achieve >90 per cent tighter constraints on S8, but also on the Hubble and dark energy equation-of-state parameters. Interestingly, we find improvements when combining these two probes only in our Stage-III set-up; in the Stage-IV scenario the lensing PDFs contain all information from the standard two-point statistics and more. This suggests that while these two probes are currently complementary, the lower noise levels of upcoming surveys will unleash the constraining power of the PDF.
Original languageEnglish
Pages (from-to)1721-1737
Number of pages17
JournalMonthly Notices of the Royal Astronomical Society
Issue number2
Early online date28 Jan 2023
Publication statusPublished - 1 Apr 2023

Keywords / Materials (for Non-textual outputs)

  • Gravitational lensing
  • Observations - cosmological parameters - large-scale structure of Universe
  • Weak - cosmology


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