Marc Lefranc is a professor of Physics at the University of Lille, France and works at the Laboratoire de Physique des Lasers, Atomes, Molécules (UMR CNRS 8523), in the physics department of the Faculty of Science and Technology. His research interests are in nonlinear dynamics and its applications. He has long worked on topological methods for characterizing chaotic behavior in experimental systems, a field of research on which he co-authored a book with Robert Gilmore ("The Topology of Chaos"). His current research activities are devoted to the mathematical modeling of circadian clocks, the biological oscillators that keep the time inside us, and of their synchronization with daily rythms. He teaches master courses in nonlinear dynamics both at an introductory and at an advanced level. M.L. has presided over the French nonlinear dynamics conference (la "Rencontre du Non-Linéaire") from 2006 to 2013 and has been a member of the organizing committee of the Experimental Chaos and Complexity Conference from 2010 to 2018.

Marion Erpelding has a PhD in physics from the University of Rennes, France. She works as a freelance illustrator.