Dark Energy Survey: Overview and BAO measurements

The Dark Energy Survey (DES) is a photometric survey that will cover 5000 square degrees in the southern sky over 5 years of observaAons. It was designed to measure the equaAon of state of dark energy with unprecedented precision. The recently published Year-1 weak lensing results showed its capability to compete with CMB experiments in measuring cosmological parameters, achieving w=-0.8±0.2 on its own and w=-1.0 ±0.05 in combinaAon with external probes. In the second part I will present preliminary results on the Baryonic AcousAc OscillaAon (BAO) angulardistance measurement from DES Year-1 data. Photometric redshiS esAmates introduce a large uncertainty in the radial posiAon of galaxies, which reduces the observed clustering. This has to be taken into account, both at the clustering measurement and at the simulaAon level, requiring new techniques on both fields. Despite this effect, DES Y1 results will provide us with a 5% precision BAO angular distance measurement at z≈0.8.