Cosmology with the moving lens effect

TL;DR

This paper proposes using the moving-lens effect to reconstruct the large-scale transverse-velocity field, enabling precise measurement of cosmological parameters like $f\sigma_8$, and overcoming limitations of other velocity measurement methods.

Contribution

It introduces a novel approach to measure the velocity field via the moving-lens effect, improving constraints on cosmological parameters beyond existing techniques.

Findings

Reconstruction of the transverse-velocity field from the moving-lens effect is feasible.

This method can measure $f\sigma_8$ with high precision.

It mitigates astrophysical uncertainties affecting other velocity measurements.

Abstract

Velocity fields can be reconstructed at cosmological scales from their influence on the correlation between the cosmic microwave background and large-scale structure. Effects that induce such correlations include the kinetic Sunyaev Zel'dovich (kSZ) effect and the moving-lens effect, both of which will be measured to high precision with upcoming cosmology experiments. Galaxy measurements also provide a window into measuring velocities from the effect of redshift-space distortions (RSDs). The information that can be accessed from the kSZ or RSDs, however, is limited by astrophysical uncertainties and systematic effects, which may significantly reduce our ability to constrain cosmological parameters such as $f\sigma_8$. In this paper, we show how the large-scale transverse-velocity field, which can be reconstructed from measurements of the moving-lens effect, can be used to measure $f\sigma_8$ to high precision.