In past century we have learned much about the origin and evolution of the Universe. We now know the Universe is 13.8 billion years old, but its main ingredients remain a mystery: atoms make up only 5%. The rest consists of dark matter and dark energy, components for which we lack a fundamental physical theory. Better observations are needed to guide theory and ESA’s Euclid satellite is designed to do just that. Euclid is scheduled for launch in 2022 and will map the distribution of dark matter in the Universe as a function of cosmic time. However many challenges remain if we want to extract accurate cosmological information from these complex data.

BIO
Henk Hoekstra is a professor of at Leiden Observatory in the Netherlands. His main area of research is observational cosmology, with a particular focus on the study of dark matter and dark energy using weak gravitational lensing. He has played leading roles in a number of large imaging surveys, and since 2011 he is a cosmology coordinator for Euclid, the ESA mission to study the nature of dark energy and many other aspects of our current cosmological paradigm.