Starting from February 1, 2026, and for six months, the CRM-CNRS welcomes Richard Griffon.

Richard GRIFFON

Lecturer, University of Clermont-Auvergne

02/01/2026 – 08/31/2026

Richard Griffon has been a lecturer at the University of Clermont Auvergne since January 2021. His work lies at the intersection of number theory and Diophantine geometry. It mainly focuses on the arithmetic of elliptic curves and abelian varieties over function fields, the asymptotic study of special values of their L-functions, in the spirit of the Brauer–Siegel theorem and its generalizations, as well as on isogenies between abelian varieties and their interactions with various notions of height. He defended his thesis in July 2016 at the University of Paris Diderot, under the supervision of Marc Hindry, on analogues of the Brauer–Siegel theorem for families of elliptic curves defined over function fields. After his thesis, he was a postdoctoral researcher at Universiteit Leiden, then at Universität Basel. He is notably a member of the GAEC (ANR) and PadLEfAn (ANR) projects, and of the international network IRN GandA (CNRS).

On January 26, 2026, the Jean-Christophe Yoccoz International Laboratory in Rio de Janeiro celebrated its twentieth anniversary in the presence of Eric Tallon, Consul General of France in Rio de Janeiro, Antoine Petit, CEO of the CNRS, Marcelo Viana, director of the Instituto de Matemática Pura e Aplicada, Impa, and Christophe Besse, director of the National Institute of Mathematical Sciences and Their Interactions, CNRS-mathematics.

On this occasion, the MATHAM research federation was inaugurated, bringing together international research laboratories in mathematics in the Americas. The following laboratories are currently part of it:

On Wednesday, January 21, Didier Lesesvre gave a presentation to the students of Collège Stanislas in Montreal. He spoke to the students about what mathematical research is and explored foundational paradoxes in the history of mathematics, showing how they led to reflections on the concept of infinity and then to working with it.

Find the entire series of popularization conferences in mathematics offered by CRM-CNRS at Collège Stanislas (French institution of the AEFE network) for the 2025-2026 academic year.

“We are always trying to find out what mathematics can be useful for while forgetting that sometimes, being useless is mainly serving the future.”
Bruno Bonell, Secretary General for Investment, in charge of the France 2030 plan.

International cooperation is fundamental in sciences in general, and in mathematics in particular. The CNRS Foundation contributes to the development and promotion of the CNRS, a French public multidisciplinary research organization.

To specifically support Franco-Quebec cooperation in mathematics, do not hesitate to go through the Foundation!

On Wednesday, January 14, Emmanuel Royer gave a presentation to the final year students of Collège Stanislas in Montreal on Fermat’s little theorem and the notion of group, an introduction to a series that will take place on February 4, during which RSA cryptography and elliptic curve cryptography will be discussed.

Every prime number unfailingly measures one of the powers -1 of some progression, and the exponent of the said power is a sub-multiple of the given prime number -1 (…). I would send you the proof, if I were not apprehensive of being too lengthy.
Pierre de Fermat, October 18, 1640.

Starting from January 4, 2026, and for six months, the CRM-CNRS welcomes Didier Lesesvre.

Didier LESESVRE

Lecturer, University of Lille

01/04/2026 – 03/07/2026

Didier Lesesvre is a lecturer at the University of Lille. His research focuses on number theory and the analytic theory of automorphic forms. He completed his thesis in Paris under the supervision of Farrell Brumley, during which he benefited from long research stays at EPFL with Ian Petrow and Philippe Michel, as well as in Göttingen with Valentin Blomer. He defended his thesis in 2018 and then worked for three years at Sun Yat-Sen University in China.

Arriving on January 1, 2025, Nicolas Crampé left the CRM-CNRS (IRL3457) on December 31, 2025.

He worked with Luc Vinet, a professor at Université de Montréal at the Laboratoire de physique mathématique. He also had the opportunity to collaborate with Quentin Labriet, a post-doctoral researcher, and Lucia Morey, a post-doctoral researcher from Luc Vinet’s team. Pierre-Antoine Bernard, with whom Nicolas Crampé has worked since his master’s internship, defended his doctorate in June 2025, and they continued their collaboration.

Emmanuel Royer
and
the mathematicians of CRM-CNRS
wish you
a 2026 full of discoveries!

On December 4, 2025, the director of the IRL traveled to the mathematics department of Laval University in Quebec for a presentation on collaboration opportunities between France and Quebec in mathematics.

These numerous opportunities are offered notably by the CNRS, the Consulate General of France in Quebec, and the Centre de recherches mathématiques (CRM) thanks to a grant from the Fonds de recherche du Québec.

Presentation file

Emmanuel Royer gave two lectures on the theme of geometries. One on November 19 for second and first-year students focused on the history of Euclid’s fifth postulate and the (long) birth of so-called non-Euclidean geometries. The other, aimed at final-year students and linked to the teaching of philosophy, also started from Euclid’s fifth postulate to invite reflection on the axiomatization of mathematics.

The topics presented were based on the document available for download and a short bibliography of the texts used to prepare these presentations is available at the end of the text available for download (which is not the text of the lectures)

The Centre national de la recherche scientifique (CNRS) in France and the Centre de recherches mathématiques (CRM) in Quebec have been associated since 2011 to co-direct an International Research Laboratory (IRL) in mathematics: the CRM-CNRS.

On October 20 and 21, a delegation from the CNRS composed of Christophe BESSE, director of the National Institute of Mathematical Sciences and Their Interactions (Insmi, CNRS-Mathematics), Frédéric HÉRAU, deputy scientific director of Insmi in charge of Europe and international affairs, Andrea DESSEN, director of the CNRS office in Canada, and Suzie BRONNER, scientific cooperation officer at the same office, visited its most attractive international laboratory in mathematics, the CRM-CNRS.

Takuvik is an international research laboratory (IRL3376), a partnership between the CNRS, Sorbonne University in France, and Laval University in Quebec (Canada) led by Philippe Archambault.

The objective of the unit is to understand the impact of current environmental disturbances of climatic and anthropogenic origin on Arctic, marine, and terrestrial ecosystems and geosystems.

On October 23 and 24, 2025, Takuvik organized its annual seminar. At the invitation of Philippe Archambault, the director of CRM-CNRS participated in the seminar on Thursday, the 23rd, with the aim of exploring collaboration possibilities, particularly on themes related to oceanography.