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Cosmological forecasts with the clustering of weak lensing peaks

Davies, Christopher T.; Cautun, Marius; Giblin, Benjamin; Li, Baojiu; Harnois-Déraps, Joachim; Cai, Yan-Chuan

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Christopher T. Davies

Marius Cautun

Benjamin Giblin

Joachim Harnois-Déraps

Yan-Chuan Cai


Maximizing the information that can be extracted from weak lensing (WL) measurements is a key goal for upcoming stage IV surveys. This is typically achieved through statistics that are complementary to the cosmic shear two-point correlation function, the most well established of which is the WL peak abundance. In this work, we study the clustering of WL peaks, and present parameter constraint forecasts for an LSST-like survey. We use the cosmo-SLICS wCDM simulations to measure the peak two-point correlation function for a range of cosmological parameters, and use the simulation data to train a Gaussian process regression emulator that is applied to generate likelihood contours and provide parameter constraint forecasts from mock observations. We investigate the dependence of the peak two-point correlation function on the peak height, and find that the clustering of low-amplitude peaks is complementary to that of high-amplitude peaks. Consequently, their combination gives significantly tighter constraints than the clustering of high peaks alone. The peak two-point correlation function is significantly more sensitive to the cosmological parameters h and w0 than the peak abundance, and when the probes are combined, constraints on Ωm, S8, h, and w0 improve by at least a factor of 2, relative to the peak abundance alone. Finally, we compare the forecasts for WL peaks and voids, and show that the two are also complementary; both probes can offer better constraints on S8 and w0 than the shear correlation function by roughly a factor of 2.

Journal Article Type Article
Acceptance Date Apr 11, 2022
Online Publication Date Apr 30, 2022
Publication Date 2022-07
Deposit Date Oct 27, 2021
Publicly Available Date Jun 8, 2022
Journal Monthly Notices of Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 513
Issue 4
Pages 4729-4746
Public URL
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Published Journal Article (4.9 Mb)

Copyright Statement
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society. ©: 2021 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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