paper

The gauge invariant cosmological Jacobi map from weak lensing at leading order

arXiv:2201.11552 · doi:10.1088/1475-7516/2022/08/052

Abstract

We compute the weak lensing Jacobi map at first order in perturbation theory and show that it is both, gauge invariant and symmetric. Linear perturbations therefore do not induce any rotation. However, vector and tensor perturbations do induce -modes in the shear. We show that contrary to what is often claimed in the literature, the shear -mode power spectrum is not fully determined by the rotation power spectrum. Also the -mode shear power spectrum is not determined by the convergence power spectrum. While this difference is small for scalar perturbations, it becomes very relevant for tensor perturbations, i.e. gravitational waves.

38 pages, 6 figures. Typos fixed. References and comments added. Accepted for publication in JCAP

References in corpus (13)