I'm a professor at the Université Paris-Saclay in Orsay, at the Institut d'Astrophysique Spatiale (IAS). I am a honorary member of the Institut Universitaire de France. I was deputy Director of IAS. Before, I was a Research Associate at the University of Arizona working on NASA's Spitzer. I'm interested in the emergence of large scale structure, esp. galaxy proto-clusters, and the role of infrared galaxies in the history of the Universe, and try to understand the physical processes driving the formation and the evolution of galaxies. I'm also interessted in understanding the relic emission of galaxies, the extragalactic background light. To do so, I'm observing galaxies and the Cosmic Infrared Background (the relic emission of galaxies) with IR space telescopes like Planck, Herschel, Spitzer or ISO and also develop new analysis tools and models. I'm heavily involved now in Euclid as well.