After a master’s degree at the Ecole Normale Supérieure in Paris, Julien obtained his PhD in Theoretical Physics from Sorbonne Université in 2022, under the supervision of Cyril Pitrou at the Institut d’Astrophysique de Paris.

Julien joined the N3AS network in 2022, spending the first two years at North Carolina State University, with Professor Gail McLaughlin as faculty host.

His research focuses on the evolution of neutrinos in a variety of situations, such as the early Universe and dense astrophysical environments (core-collapse supernovae, neutron star mergers). An accurate modelling of neutrino transport in these environments remains a major challenge. He is particularly interested in constraining neutrino physics beyond the Standard Model, using its consequences on probes such as Big-Bang Nucleosynthesis, the Cosmic Microwave Background or the dynamics of the astrophysical environments mentioned above.