Multiprobe cosmology from the abundance of SPT clusters and DES galaxy clustering and weak lensing
Journal Article
Overview
abstract
Cosmic shear, galaxy clustering, and the abundance of massive halos each probe the large-scale structure of the Universe in complementary ways. We present cosmological constraints from the joint analysis of the three probes, building on the latest analyses of the lensing-informed abundance of clusters identified by the South Pole Telescope (SPT) and of the auto- and cross-correlation of galaxy position and weak lensing measurements (3×2pt) in the Dark Energy Survey (DES). We consider the cosmological correlation between the different tracers and we account for the systematic uncertainties that are shared between the large-scale lensing correlation functions and the small-scale lensing-based cluster mass calibration. Marginalized over the remaining Λ cold dark matter (ΛCDM) parameters (including the sum of neutrino masses) and 52 astrophysical modeling parameters, we measure Ωm=0.300±0.017 and σ8=0.797±0.026. Compared to constraints from primary cosmic microwave background (CMB) anisotropies, our constraints are only 15% wider with a probability to exceed of 0.22 (1.2σ) for the two-parameter difference. We further obtain S8≡σ8(Ωm/0.3)0.5=0.796±0.013 which is lower than the measurement at the 1.6σ level. The combined SPT cluster, DES 3×2pt, and datasets mildly prefer a nonzero positive neutrino mass, with a 95% upper limit ∑mν<0.25eV on the sum of neutrino masses. Assuming a wCDM model, we constrain the dark energy equation of state parameter w=−1.15−0.17+0.23 and when combining with primary CMB anisotropies, we recover w=−1.20−0.09+0.15, a 1.7σ difference with a cosmological constant. The precision of our results highlights the benefits of multiwavelength multiprobe cosmology and our analysis paves the way for upcoming joint analyses of next-generation datasets.
