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The accuracy of weak lensing simulations

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journal contribution
posted on 2023-06-09, 20:59 authored by Stefan Hilbert, Alexandre Barreira, Giulio Fabbian, Pablo Fosalba, Carlo Giocoli, Sownak Bose, Matteo Calabrese, Carmelita Carbone, Christopher T Davies, Baojiu Li, Claudio Llinares, 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 per cent out to scales l ˜ 4000. For lensing peak counts, the agreement is better than 5 per cent 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.

Funding

Astrophysics and Cosmology - Sussex Consolidated Grant; G1291; STFC-SCIENCE AND TECHNOLOGY FACILITIES COUNCIL; ST/L000652/1

Precision cosmological parameters : CosmoPars; G1365; EUROPEAN UNION; 616170 ERC-2013-CoG

History

Publication status

  • Published

File Version

  • Published version

Journal

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

Publisher

Oxford University Press

Issue

1

Volume

493

Page range

305-319

Department affiliated with

  • Physics and Astronomy Publications

Research groups affiliated with

  • Astronomy Centre Publications

Full text available

  • Yes

Peer reviewed?

  • Yes

Legacy Posted Date

2020-03-27

First Open Access (FOA) Date

2020-03-27

First Compliant Deposit (FCD) Date

2020-03-26

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