Speaker
Description
We present cosmological constraints from the full six-year Dark Energy Survey (DES) combining weak gravitational lensing and galaxy clustering in a joint 3 $\times$ 2pt analysis over $\sim$5000 sq. deg. This represents the legacy large-scale structure result of DES, culminating more than a decade of survey operations and analysis development. We derive constraints on $\Lambda$CDM and several extensions. The $\Lambda$CDM analysis yields $S_8 = 0.789 \pm 0.012$ and $\Omega_m = {0.333}^{+0.023}_{-0.028}$, and we discuss the consistency of these results with CMB primary anisotropy constraints. We also present the first combination of all four DES dark-energy probes: 3 $\times$ 2pt, SNe Ia, BAO, and clusters. Beyond the cosmological results, we reflect on key lessons from this final DES analysis and discuss what these imply for the coming generation of cosmic surveys.