Precision calculations of the cosmic shear power spectrum projection
We compute the spherical-sky weak-lensing power spectrum of the shear and convergence. We discuss various approximations, such as flat-sky, and first- and second-order Limber equations for the projection. We find that the impact of adopting these approximations is negligible when constraining cosmol...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Journal article |
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Oxford University Press
2017
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| _version_ | 1797067666601541632 |
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| author | Kilbinger, M Heymans, C Asgari, M Joudaki, S Schneider, P Simon, P Van Waerbeke, L Harnois-Déraps, J Hildebrandt, H Köhlinger, F Kuijken, K Viola, M |
| author_facet | Kilbinger, M Heymans, C Asgari, M Joudaki, S Schneider, P Simon, P Van Waerbeke, L Harnois-Déraps, J Hildebrandt, H Köhlinger, F Kuijken, K Viola, M |
| author_sort | Kilbinger, M |
| collection | OXFORD |
| description | We compute the spherical-sky weak-lensing power spectrum of the shear and convergence. We discuss various approximations, such as flat-sky, and first- and second-order Limber equations for the projection. We find that the impact of adopting these approximations is negligible when constraining cosmological parameters from current weak-lensing surveys. This is demonstrated using data from the Canada–France–Hawaii Telescope Lensing Survey.We find that the reported tension with Planck cosmic microwave background temperature anisotropy results cannot be alleviated. For future large-scale surveys with unprecedented precision, we show that the spherical second-order Limber approximation will provide sufficient accuracy. In this case, the cosmic-shear power spectrum is shown to be in agreement with the full projection at the sub-percent level for ℓ > 3, with the corresponding errors an order of magnitude below cosmic variance for all ℓ. When computing the two-point shear correlation function, we show that the flat-sky fast Hankel transformation results in errors below two percent compared to the full spherical transformation. In the spirit of reproducible research, our numerical implementation of all approximations and the full projection are publicly available within the package NICAEA at http://www.cosmostat.org/software/nicaea. |
| first_indexed | 2024-03-06T21:59:38Z |
| format | Journal article |
| id | oxford-uuid:4e227de6-e04a-4282-9c20-4e6c973834bb |
| institution | University of Oxford |
| last_indexed | 2024-03-06T21:59:38Z |
| publishDate | 2017 |
| publisher | Oxford University Press |
| record_format | dspace |
| spelling | oxford-uuid:4e227de6-e04a-4282-9c20-4e6c973834bb2022-03-26T15:59:29ZPrecision calculations of the cosmic shear power spectrum projectionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4e227de6-e04a-4282-9c20-4e6c973834bbSymplectic Elements at OxfordOxford University Press2017Kilbinger, MHeymans, CAsgari, MJoudaki, SSchneider, PSimon, PVan Waerbeke, LHarnois-Déraps, JHildebrandt, HKöhlinger, FKuijken, KViola, MWe compute the spherical-sky weak-lensing power spectrum of the shear and convergence. We discuss various approximations, such as flat-sky, and first- and second-order Limber equations for the projection. We find that the impact of adopting these approximations is negligible when constraining cosmological parameters from current weak-lensing surveys. This is demonstrated using data from the Canada–France–Hawaii Telescope Lensing Survey.We find that the reported tension with Planck cosmic microwave background temperature anisotropy results cannot be alleviated. For future large-scale surveys with unprecedented precision, we show that the spherical second-order Limber approximation will provide sufficient accuracy. In this case, the cosmic-shear power spectrum is shown to be in agreement with the full projection at the sub-percent level for ℓ > 3, with the corresponding errors an order of magnitude below cosmic variance for all ℓ. When computing the two-point shear correlation function, we show that the flat-sky fast Hankel transformation results in errors below two percent compared to the full spherical transformation. In the spirit of reproducible research, our numerical implementation of all approximations and the full projection are publicly available within the package NICAEA at http://www.cosmostat.org/software/nicaea. |
| spellingShingle | Kilbinger, M Heymans, C Asgari, M Joudaki, S Schneider, P Simon, P Van Waerbeke, L Harnois-Déraps, J Hildebrandt, H Köhlinger, F Kuijken, K Viola, M Precision calculations of the cosmic shear power spectrum projection |
| title | Precision calculations of the cosmic shear power spectrum projection |
| title_full | Precision calculations of the cosmic shear power spectrum projection |
| title_fullStr | Precision calculations of the cosmic shear power spectrum projection |
| title_full_unstemmed | Precision calculations of the cosmic shear power spectrum projection |
| title_short | Precision calculations of the cosmic shear power spectrum projection |
| title_sort | precision calculations of the cosmic shear power spectrum projection |
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