Constraining warm dark matter with cosmic shear power spectra

TL;DR

This paper explores how cosmic shear measurements can constrain the mass of warm dark matter particles, using analytical models and forecasts for future surveys like Euclid and Planck.

Contribution

It introduces a comparison of analytical approaches to model non-linear warm dark matter power spectra for cosmological constraints.

Findings

A Euclid-like survey combined with Planck data could set a lower limit of 2.5 keV on warm dark matter particle mass.

The study demonstrates the importance of modeling choices in constraining dark matter properties.

Using conservative modeling approaches provides robust lower bounds on dark matter particle mass.

Abstract

We investigate potential constraints from cosmic shear on the dark matter particle mass, assuming all dark matter is made up of light thermal relic particles. Given the theoretical uncertainties involved in making cosmological predictions in such warm dark matter scenarios we use analytical fits to linear warm dark matter power spectra and compare (i) the halo model using a mass function evaluated from these linear power spectra and (ii) an analytical fit to the non-linear evolution of the linear power spectra. We optimistically ignore the competing effect of baryons for this work. We find approach (ii) to be conservative compared to approach (i). We evaluate cosmological constraints using these methods, marginalising over four other cosmological parameters. Using the more conservative method we find that a Euclid-like weak lensing survey together with constraints from the Planck cosmic microwave background mission primary anisotropies could achieve a lower limit on the particle mass of 2.5 keV.