A senior researcher, Reynald Pain holds a PhD in theoretical physics. Having joined the CNRS in 1985, he pursued his research at CERN, working on the CHARM and then the Dephi experiments. In 1991, he became head of the Dephi team at the Laboratoire de physique nucléaire et hautes énergies (LPNHE, CNRS/UPMC/Université Paris Diderot) before dedicating part of his work to observational cosmology. He spent two years at the University of California, Berkeley (US), where he was involved in the birth of the Supernova Cosmology Project. After returning to France, he initiated several international projects on supernovae and involved French teams in the Large Synoptic Survey Telescope. From 2009 to 2014, he directed the LPNHE. Prior to being named head of the IN2P3 in December 2015, he was deputy scientific director for "Astroparticles and Neutrinos" and leader of the Supernova Cosmology Project.