The CRM-CNRS will hold the general assembly of its scientific staff on September 8, 2024, at 11 AM in room 5374-1.

Starting from September 1^st, 2025, the IRL CRM-CNRS will host six scientists for long-term stays.

Nicolas CRAMPÉ

Researcher, CNRS

01/09/2025 – 31/12/2025

After studying at the École supérieure de physique et de chimie industrielles de la Ville de Paris (ESPCI Paris), Nicolas Crampé completed a PhD at the Annecy Laboratory of Theoretical Physics (LAPTh) at the University of Savoie. Recruited by CNRS in 2009, he worked at the University of Montpellier and, since 2018, at the University of Tours.
Specializing in exactly solvable systems and representation theory, Nicolas Crampé uses algebraic tools to explore the underlying symmetries of various physical problems. His research focuses on the calculation of entanglement entropies in quantum mechanics, the evaluation of average values in out-of-equilibrium statistical models, and the spectral analysis of Hamiltonians. More recently, he has also been interested in certain special functions and their role in the study of algebraic representations, association schemes, and integrable quantum models.

Arrived on September 1^st, 2024, Nicolas Bousquet left the CRM-CNRS (IRL3457) on August 31, 2025.

He was able to work with his collaborators from the Laboratory of Algebra, Combinatorics, and Mathematical Computer Science (Lacim), notably Adrian Vetta from McGill University and his students, as well as Ndiame Ndiaye (a PhD student at McGill University). He also took advantage of the time zone proximity to develop his work with Daniel Cranston (Virginia Commonwealth University) and Naomi Nishimura (University of Waterloo) and her students.

Arrived on September 1^st, 2024, Ewen Gallic left the CRM-CNRS (IRL3457) on August 31, 2025.

He worked with Arthur Charpentier, a professor at the Université du Québec à Montréal.

During his stay, he completed a number of works:

• Fernandes Machado, A., Charpentier, A., Gallic, E. Optimal Transport on Categorical Data for Counterfactuals using Compositional Data and Dirichlet Transport arXiv (forthcoming, IJCAI). Associated Ebook ;
• Fernandes Machado, A., Charpentier, A., Gallic, E. (2025. Sequential Conditional (Marginally Optimal) Transport on Probabilistic Graphs for Interpretable Counterfactual Fairness. Proceedings of the AAAI Conference on Artificial Intelligence, 39(18), 19358-19366. Associated Poster. Associated Ebook ;
• Fernandes Machado, A., Charpentier, A., Flachaire, E., Gallic, E., Hu, F. (2024). Post-Calibration Techniques: Balancing Calibration and Score Distribution Alignment. NeurIPS 2024 Workshop on Bayesian Decision-making and Uncertainty. Associated Poster. Associated Ebook ;
• Crofils, C., Gallic, E., Vermandel, G. (2025). The Dynamic Effects of Weather Shocks on Agricultural Production. Journal of Environmental Economics and Management, 130, 103078. Associated Ebook ;

and initiated others, of which the following are sufficiently advanced to have been partially made public:

Arriving on September 1^st, 2023, Michèle Couderette left the CRM-CNRS (IRL3457) on August 31, 2025.

She was able to collaborate with

• Fabienne Venant, professor at the Université du Québec à Montréal ;
• Mireille Saboya Mandico, professor at the Université du Québec à Montréal ;
• Khoi Mai Huy, professor at the Université du Québec en Abitibi-Témiscamingue ;
• Mélanie Tremblay, professor at the Université du Québec à Rimouski ;
• Sabrina Héroux, professor at the Université du Québec à Montréal.

She was also co-responsible for the working group “Professional Development and Collaborative Work” during the 2025 conference of the Francophone Mathematical Space in Montreal.

Arrived on September 1^st, 2023, Sébastien Darses left the CRM-CNRS (IRL3457) on August 31, 2025.

He was able to take advantage of the great wealth of the CRM to interact with members of the laboratories of probability, analysis, and number theory

In particular, he developed work with

• Alessandro Fazzari, then a post-doctoral researcher at Université de Montréal ;
• Berend Ringeling, post-doctoral researcher at Université de Montréal

The following works were published or completed during Sébastien Darses’ stay at CRM-CNRS:

Arrived on November 1^st, 2024, Pierre Baumann left the CRM-CNRS (IRL3457) on June 30, 2025.

He was able to work with his collaborators from the Laboratory of Algebra, Combinatorics, and Mathematical Computer Science (Lacim), notably Joel Kamnitzer from McGill University and Hugh R. Thomas from the Université du Québec à Montreal.

Pierre Baumann is a research officer at the CNRS assigned to the CRM-CNRS.

The CRM-CNRS is holding its internal seminar on Tuesday, June 17, 2025, in room 4336 (André Aisenstadt Pavilion, University of Montreal), from 9:30 AM to 1:00 PM.

Four scientific presentations will be given by:

• Nicolas Crampé;
• Claire Guerrier;
• Ewen Gallic;
• Thierry Daudé.

Program

9:30 AM: Nicolas Crampé

10:15 AM: Claire Guerrier

Following the maximum in the heat equation: signal propagation and myelin plasticity.

How do the characteristics of the myelin sheath influence the transmission of action potentials in myelinated axons, and vice versa? To answer this question, we develop a model of signal transmission in a myelinated axon, where myelinated compartments alternate with the nodes of Ranvier. By combining a computational approach with mathematical analysis, we seek an analytical solution corresponding to the propagation of the signal in a myelin compartment, and we study the signal transmission time as a function of different neuronal morphologies.

The CRM-CNRS supported and participated in the scientific meeting “Women and Mathematics in Interaction” which took place on June 12, 2025, at the André-Aisenstadt Pavilion of the University of Montreal.

The CRM-CNRS supports the Francophone Mathematical Space 2025 colloquium by funding the participation of one male and one female mathematician working in France, co-responsible for the working groups:

• Professional Development and Collaborative Work;
• Teaching Mathematics at Post-Secondary, Higher Education, and Vocational Tracks.

This colloquium will take place from May 26 to 30, 2025, at the Université du Québec à Montréal.

The scientific meetings of the Francophone Mathematical Space have been held every three years since 2000. They are recognized as regional conferences of the International Commission on Mathematical Instruction (ICMI). They are aimed at various stakeholders concerned with issues related to the teaching of mathematics.

On Tuesday, May 6, 2025, the French Consulate General in Quebec organized a breakfast for the network of French scientists in Montreal at the École de technologie supérieure de Montréal.

Several colleagues from CRM-CNRS enjoyed this moment to meet with colleagues from all disciplines

On April 15, 2025, the international Mathematical Modeling Center in Santiago, Chile, will celebrate its anniversary in the presence of Chilean state authorities, including the President of the Republic of Chile, Gabriel Boric, representatives from the academic, scientific, and private sectors, as well as a delegation from the CNRS and the French ambassador to Chile, Cyrille Rogeau.

The Mathematical Modeling Center is the first mixed unit of the CNRS established outside of France.