The striking discovery that the expansion of the Universe is not slowing down but accelerating has turned into one of the main mysteries in Cosmology. Large observational campaigns are being developed to seed light on this and other problems. I will briefly review this effort and then discuss The Dark Energy Survey (DES) : a state-of-the-art large-scale galaxy survey designed to understand, primarily, such acceleration by mapping 5000 deg$^2$ measuring the positions and shapes for 300 million galaxies up to redshift ~ 1, the light-curves of several thousand supernovae, and the masses of tens of thousands of galaxy clusters. I will present the latest cosmological results from the first year of observations, in particular those related to the combination of large-scale structure and weak gravitational lensing, and how they compare with those from other data-sets.
|Parallel Session||Cosmology and Gravitational Waves|