Probing the cosmological principle with weak lensing shear

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Date

2025

Journal Title

Journal ISSN

Volume Title

Publisher

Institute of Physics

Abstract

The Cosmological Principle is a cornerstone of the standard model of cosmology and shapes how we view the Universe and our place within it. It is imperative, then, to devise multiple observational tests which can identify and quantify possible violations of this foundational principle. One possible method of probing large-scale anisotropies involves the use of weak gravitational lensing. We revisit this approach in order to analyse the imprint of late-time anisotropic expansion on cosmic shear. We show that the cross-correlation of shear Eand B-modes on large scales can be used to constrain the magnitude (and possibly direction) of anisotropic expansion. We estimate the signal to noise for multipoles 10 ≲ ℓ ≲ 100 that is achievable by a Euclid-like survey. Our findings suggest that such a survey could detect the E-B signal for reasonable values of the late-time anisotropy parameter.

Description

Keywords

Gravitational lensing, Redshift surveys, Weak gravitational lensing, Cosmological Principle, Modelling anisotropic expansion

Citation

Adam, J., Maartens, R., Larena, J. and Clarkson, C., 2025. Probing the Cosmological Principle with weak lensing shear. Journal of Cosmology and Astroparticle Physics, 2025(02), p.016.