# Constraints on decaying dark matter from weak lensing and cluster counts

## TL;DR

This paper constrains the lifetime of decaying dark matter using a combination of cosmological data, including CMB, cosmic shear, and galaxy cluster counts, employing N-body simulations to improve the analysis.

## Contribution

It extends previous work by incorporating N-body simulations to assess the impact of decaying dark matter on halo mass functions and cluster counts.

## Key findings

- Lower bound on dark matter lifetime: ≥ 175 Gyr.
- Combined cosmological data constrains dark matter decay.
- N-body simulations improve understanding of DDM effects.

## Abstract

We revisit a cosmological constraint on dark matter decaying into dark radiation at late times. In Enqvist et al. (2015), we mainly focused on the effects of decaying dark matter (DDM) on the cosmic microwave background (CMB) and nonlinear matter power spectrum. Extending our previous analysis, here we use N-body simulation to investigate how DDM affects the halo mass function. This allows us to incorporate the cluster counts observed by the Sunyaev-Zel'dovich effect to study a bound on the lifetime of DDM. We also update the data of CMB and cosmic shear power spectrum with the Planck 2015 results and KiDS450 observations, respectively. From these cosmological observations, we obtain an lower bound on the lifetime $\Gamma^{-1}\ge 175\,$Gyr from the Planck2015 results (CMB+SZ cluster count) combined with the KiDS450 and the recent measurements of the baryon acoustic scale.