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The accuracy of weak lensing simulations

Hilbert, Stefan; Barreira, Alexandre; Fabbian, Giulio; Fosalba, Pablo; Giocoli, Carlo; Bose, Sownak; Calabrese, Matteo; Carbone, Carmelita; Davies, Christopher T.; Li, Baojiu; Llineares, Claudio; Monaco, Pierluigi

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Stefan Hilbert

Alexandre Barreira

Giulio Fabbian

Pablo Fosalba

Carlo Giocoli

Sownak Bose

Matteo Calabrese

Carmelita Carbone

Christopher T. Davies

Claudio Llineares

Pierluigi Monaco


We investigate the accuracy of weak lensing simulations by comparing the results of five independently developed lensing simulation codes run on the same input N-body simulation. Our comparison focuses on the lensing convergence maps produced by the codes, and in particular on the corresponding PDFs, power spectra and peak counts. We find that the convergence power spectra of the lensing codes agree to ≲ 2% out to scales ℓ ≈ 4000. For lensing peak counts, the agreement is better than 5% for peaks with signal-to-noise ≲ 6. We also discuss the systematic errors due to the Born approximation, line-of-sight discretization, particle noise and smoothing. The lensing codes tested deal in markedly different ways with these effects, but they none the less display a satisfactory level of agreement. Our results thus suggest that systematic errors due to the operation of existing lensing codes should be small. Moreover their impact on the convergence power spectra for a lensing simulation can be predicted given its numerical details, which may then serve as a validation test.

Journal Article Type Article
Acceptance Date Jan 24, 2020
Online Publication Date Feb 5, 2020
Publication Date Mar 31, 2020
Deposit Date Oct 25, 2019
Publicly Available Date Feb 5, 2020
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 493
Issue 1
Pages 305-319
Public URL
Related Public URLs


Accepted Journal Article (2.8 Mb)

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

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