Cosmological Constraints from Dark Energy Survey Year 1 Cluster Lensing and Abundances with Simulation-based Forward-Modeling

TL;DR

This paper introduces a simulation-based forward-modeling framework for cosmological inference from galaxy cluster data, applied to DES Year 1 results, providing constraints consistent with other measurements and demonstrating its potential for future surveys.

Contribution

The paper develops and applies a novel simulation-based forward-modeling approach for cosmological analysis of galaxy clusters, incorporating optical selection, miscentering, and baryonic effects.

Findings

Constraints on mbda CDM parameters consistent with other measurements

Demonstrates the method's agreement with Planck data within 2.58c sigma

Establishes forward-modeling as a promising tool for Stage IV surveys

Abstract

We present a simulation-based forward-modeling framework for cosmological inference from optical galaxy-cluster samples, and apply it to the abundance and weak-lensing signals of DES-Y1 redMaPPer clusters. The model embeds cosmology-dependent optical selection using a counts-in-cylinders approach, while also accounting for cluster miscentering and baryonic feedback in lensing. Applied to DES-Y1, and assuming a flat $\Lambda$CDM cosmology, we obtain $\Omega_m=0.254^{+0.026}_{-0.020}$ and $\sigma_8=0.826^{+0.030}_{-0.034}$, consistent with a broad suite of low-redshift structure measurements, including recent full-shape analyses, the DES/KiDS/HSC 3$\times$2 results, and most cluster-abundance studies. Our results are also consistent with \textit{Planck}, with the difference being significant at $2.58\sigma$. These results establish simulation-based forward-modeling of cluster abundances as a promising new tool for precision cosmology with Stage~IV survey data.