Testing the cosmic shear spatially-flat universe approximation with generalized lensing and shear spectra

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  • Peter L. Taylor, Univ Coll London, University College London, University of London, Mullard Space Sci Lab
  • ,
  • Thomas D. Kitching, Univ Coll London, University College London, University of London, Mullard Space Sci Lab
  • ,
  • Jason D. McEwen, Univ Coll London, University College London, University of London, Mullard Space Sci Lab
  • ,
  • Thomas Tram

We introduce the Generalised Lensing and Shear Spectra (GLASS) code which is available for download from https://github.com/astro-informatics/GLaSS It is a fast and flexible public code, written in PYTHON, that computes generalized spherical cosmic shear spectra. The commonly used tomographic and spherical Bessel lensing spectra come as built-in run-mode options. GLaSS is integrated into the COSMOSIS modular cosmological pipeline package. We outline several computational choices that accelerate the computation of cosmic shear power spectra. Using GLASS, we test whether the assumption that using the lensing and projection kernels for a spatially-flat universe-in a universe with a small amount of spatial curvature-negligibly impacts the lensing spectrum. We refer to this assumption as the spatially-flat universe approximation, that has been implicitly assumed in all cosmic shear studies to date. We confirm that the spatially-flat universe approximation has a negligible impact on Stage IV cosmic shear experiments.

Original languageEnglish
Article number023522
JournalPhysical Review D
Volume98
Issue2
Number of pages6
ISSN2470-0010
DOIs
Publication statusPublished - 2018

    Research areas

  • MICROWAVE BACKGROUND ANISOTROPIES, POWER SPECTRUM, COMPUTATION

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