We present cosmological constraints from the Dark Energy Survey ( DES ) using a combined analysis of angular clustering of red galaxies and their cross-correlation with weak gravitational lensing of background galaxies .
We use a 139 square degree contiguous patch of DES data from the Science Verification ( SV ) period of observations .
Using large scale measurements , we constrain the matter density of the Universe as \Omega _ { m } = 0.31 \pm 0.09 and the clustering amplitude of the matter power spectrum as \sigma _ { 8 } = 0.74 \pm 0.13 after marginalizing over seven nuisance parameters and three additional cosmological parameters .
This translates into S _ { 8 } \equiv \sigma _ { 8 } ( \Omega _ { m } / 0.3 ) ^ { 0.16 } = 0.74 \pm 0.12 for our fiducial lens redshift bin at 0.35 < z < 0.5 , while S _ { 8 } = 0.78 \pm 0.09 using two bins over the range 0.2 < z < 0.5 .
We study the robustness of the results under changes in the data vectors , modelling and systematics treatment , including photometric redshift and shear calibration uncertainties , and find consistency in the derived cosmological parameters .
We show that our results are consistent with previous cosmological analyses from DES and other data sets and conclude with a joint analysis of DES angular clustering and galaxy-galaxy lensing with Planck CMB data , Baryon Accoustic Oscillations and Supernova type Ia measurements .