Using a hundred million galaxies in the largest galaxy catalog ever produced, the Dark Energy Survey has placed stringent constraints on the composition of the universe and the growth of large-scale structure. However, with great statistical power comes great responsibility. I will discuss how we use the images we capture to constrain cosmology, and some of the techniques that we have developed to defend against multiple sources of systematic bias in the measurements which, if untreated, could lead to spurious detections of new physics. I will focus on the treatment of imaging systematics in galaxy clustering, a key challenge in many current and future surveys, but also touch on more general techniques for scaling up robustness tests in the context of large collaborations, as will be critical for future surveys to accurately and confidently deliver on their science goals
Jonás Chaves Montero, Andreu Font Ribera, Martine Lokken