Imprints of dynamical dark energy on weak-lensing measurements

TL;DR

This paper demonstrates that scalar-field dark energy models can significantly enhance weak-lensing power spectra compared to LCDM, with potential detectability by future large telescopes.

Contribution

It provides linear perturbation theory calculations showing how specific dark energy models affect weak-lensing measurements, highlighting observable enhancements.

Findings

Enhancement of lensing power spectrum up to 40% on degree scales.

Dark energy clustering contributes to large-scale power increases.

Potential for detection with next-generation telescopes.

Abstract

We show that simple models of scalar-field dark energy leave a generic enhancement in the weak-lensing power spectrum when compared to the LCDM prediction. In particular, we calculate the linear-scale enhancement in the convergence (or cosmic-shear) power spectrum for two best-fit models of scalar-field dark energy, namely, the Ratra-Peebles and SUGRA-type quintessence. Our calculations are based on linear perturbation theory, using gauge-invariant variables with carefully defined adiabatic initial conditions. We find that geometric effects enhance the lensing power spectrum on a broad range of scales, whilst the clustering of dark energy gives rise to additional power on large scales. The dark-energy power spectrum for these models are also explicitly obtained. On degree scales, the total enhancement may be as large as 30-40% for sources at redshift ~1. We argue that there are realistic prospects for detecting such an enhancement using the next generation of large telescopes.