UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Post-Limber weak lensing bispectrum, reduced shear correction, and magnification bias correction

Deshpande, AC; Kitching, TD; (2020) Post-Limber weak lensing bispectrum, reduced shear correction, and magnification bias correction. Physical Review D , 101 (10) , Article 103531. 10.1103/PhysRevD.101.103531. Green open access

[thumbnail of PhysRevD.101.103531.pdf]
Preview
Text
PhysRevD.101.103531.pdf - Published Version

Download (1MB) | Preview

Abstract

The significant increase in precision that will be achieved by Stage IV cosmic shear surveys means that several currently used theoretical approximations may cease to be valid. An additional layer of complexity arises from the fact that many of these approximations are interdependent; the procedure to correct for one involves making another. Two such approximations that must be relaxed for upcoming experiments are the reduced shear approximation and the effect of neglecting magnification bias. Accomplishing this involves the calculation of the convergence bispectrum; typically subject to the Limber approximation. In this work, we compute the post-Limber convergence bispectrum, and the post-Limber reduced shear and magnification bias corrections to the angular power spectrum for a Euclid-like survey. We find that the Limber approximation significantly overestimates the bispectrum when any side of the bispectrum triangle, ℓ i < 60 . However, the resulting changes in the reduced shear and magnification bias corrections are well below the sample variance for ℓ ≤ 5000 . We also compute a worst-case scenario for the additional biases on w 0 w a CDM cosmological parameters that result from the difference between the post-Limber and Limber approximated forms of the corrections. These further demonstrate that the reduced shear and magnification bias corrections can safely be treated under the Limber approximation for upcoming surveys.

Type: Article
Title: Post-Limber weak lensing bispectrum, reduced shear correction, and magnification bias correction
Open access status: An open access version is available from UCL Discovery
DOI: 10.1103/PhysRevD.101.103531
Publisher version: https://doi.org/10.1103/PhysRevD.101.103531
Language: English
Additional information: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Cosmology, Dark energy, Dark matter, Gravitational lenses, Large scale structure of the Universe
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics
URI: https://discovery.ucl.ac.uk/id/eprint/10102369
Downloads since deposit
52Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item