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Jean-Sebastien Gagnon

  • Assistant Professor


Jean-Sebastien Gagnon joined the physics department of Norwich University in 2019.

In 2007, he completed his Ph.D. in theoretical high-energy physics at McGill University, where he worked on computing transport coefficients in hot gauge field theories under the supervision of S. Jeon. After earning his doctorate, he joined the group of M. Shaposhnikov as a postdoc at Ecole Polytechnique Federale de Lausanne to research baryogenesis (a fancy word to say “Why is there more matter than antimatter in the universe”). He completed another postdoc with the group of J. Berges at the Technical University Darmstadt, where he worked on non-equilibrium quantum field theory, transport coefficients, and dark energy (another fancy word to say “Why is the rate of expansion of the universe increasing with time?") A common theme of his early research is (equilibrium and non-equilibrium) field theory applied to problems in particle physics and cosmology.

His career took a different turn after spending a few years as a postdoc/associate in the lab of J. Perez-Mercader at Harvard. While there, he applied field theory to chemical systems of the reaction-diffusion type that mimic some aspects of living systems. More specifically, he is applying dynamical renormalization group techniques to those “living” chemical systems to study the effect of the environment on their behavior. He was also part of Harvard’s “Origins of Life Initiative,” in which he was exposed to the fascinating world of astrobiology. He is now interested in chemical systems that model the transition between deterministic chemistry and “living” chemistry at the origin of life (such as autocatalytic sets), using a combination of theoretical tools (field theory, network theory, etc.) and numerical simulations.

On the teaching side, Professor Gagnon is passionate about physics and tries his best to share that passion with his students. He loves to incorporate unusual examples in his lectures (such as “How many laser pointers are necessary to stop the Earth’s rotation”), many of them coming from his readings on science fiction and fantasy, of which he is a big fan. He even published a paper on the physical (im)possibility of lightsabers in an educational journal, in order to introduce nonlinear electrodynamics to students with an undergraduate physics background. His enthusiasm and dedication earned him the Castleton University Endowed Part-Time Faculty Award in 2018.

Visit Professor Gagnon’s Google Scholar profile for a complete list of his publications.



Ph.D. McGill University

Courses Taught

PS 211 University Physics I
PS 212 University Physics II
PS 444 Quantum Physics


Gagnon, J.-S. and D. Hochberg, ""Conditions for the origin of homochirality in primordial catalytic reaction networks"", Scientific Reports 13 (1), 9885 (2023).

Muñuzuri, A. P., J.-S Gagnon and J. Pérez-Mercader, ""Numerical and renormalization group analysis of the phase diagram of a stochastic cubic autocatalytic reaction-diffusion system"", Phys. Rev. E 107 (3), 034213 (2023).

Butch, C. J., M. Meringer, J.-S. Gagnon and H. J. Cleaves, ""Open questions in understanding life’s origins"", Communications Chemistry 4 (1), 11 (2021).