Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
Abstract
We present the first cosmology results from large-scale structure in the Dark
Energy Survey (DES) spanning 5000 deg$^2$. We perform an analysis combining
three two-point correlation functions (3$\times$2pt): (i) cosmic shear using
100 million source galaxies, (ii) galaxy clustering, and (iii) the
cross-correlation of source galaxy shear with lens galaxy positions. The
analysis was designed to mitigate confirmation or observer bias; we describe
specific changes made to the lens galaxy sample following unblinding of the
results. We model the data within the flat $\Lambda$CDM and $w$CDM cosmological
models. We find consistent cosmological results between the three two-point
correlation functions; their combination yields clustering amplitude
$S_8=0.776^{+0.017}_{-0.017}$ and matter density $\Omega_{\mathrm{m}} =
0.339^{+0.032}_{-0.031}$ in $\Lambda$CDM, mean with 68% confidence limits;
$S_8=0.775^{+0.026}_{-0.024}$, $\Omega_{\mathrm{m}} = 0.352^{+0.035}_{-0.041}$,
and dark energy equation-of-state parameter $w=-0.98^{+0.32}_{-0.20}$ in
$w$CDM. This combination of DES data is consistent with the prediction of the
model favored by the Planck 2018 cosmic microwave background (CMB) primary
anisotropy data, which is quantified with a probability-to-exceed $p=0.13$ to
$0.48$. When combining DES 3$\times$2pt data with available baryon acoustic
oscillation, redshift-space distortion, and type Ia supernovae data, we find
$p=0.34$. Combining all of these data sets with Planck CMB lensing yields joint
parameter constraints of $S_8 = 0.812^{+0.008}_{-0.008}$, $\Omega_{\mathrm{m}}
= 0.306^{+0.004}_{-0.005}$, $h=0.680^{+0.004}_{-0.003}$, and $\sum m_{\nu}<0.13
\;\mathrm{eV\; (95\% \;CL)}$ in $\Lambda$CDM; $S_8 = 0.812^{+0.008}_{-0.008}$,
$\Omega_{\mathrm{m}} = 0.302^{+0.006}_{-0.006}$, $h=0.687^{+0.006}_{-0.007}$,
and $w=-1.031^{+0.030}_{-0.027}$ in $w$CDM. (abridged)
Type
Journal articlePermalink
https://hdl.handle.net/10161/24146Collections
More Info
Show full item recordScholars@Duke
Daniel M. Scolnic
Associate Professor of Physics
Use observational tools to measure the expansion history of the universe. Trying
to answer big questions like 'what is dark energy?'.
Michael A. Troxel
Associate Professor of Physics
Alphabetical list of authors with Scholars@Duke profiles.

Articles written by Duke faculty are made available through the campus open access policy. For more information see: Duke Open Access Policy
Rights for Collection: Scholarly Articles
Works are deposited here by their authors, and represent their research and opinions, not that of Duke University. Some materials and descriptions may include offensive content. More info