Pierre LE BRIS

Currently Postdoc at Institut des Hautes Etudes Scientifiques (IHES) mentored by Thierry BODINEAU.

Before that, I was a PhD student in Applied Mathematics at Laboratoire Jacques-Louis Lions (LJLL), Sorbonne Université, under the joint supervision of Arnaud GUILLIN and Pierre MONMARCHÉ.


Keywords: Probability, System of interacting particles, Mean-field limits.



Announcement: This year I'm co-organizing a working group in Jussieu on Markov Processes, about problems of long-time convergence, particle systems and stochastic algorithms among other things. Do not hesitate to contact me if you are interested!

CONTACT

Organization: IHES

E-mail: lebris [AT] ihes [DOT] fr

Mail:
Office 1E9
Institut des Hautes Etudes Scientifiques,
35 route de Chartres,
91440 Bures-sur-Yvette,
FRANCE

EDUCATION AND POSITIONS

• 2023-2025: Postdoc (Huawei Young Talents Program) mentored by Thierry BODINEAU at IHES, Bures-sur-Yvette, France.
• 2020-2023: PhD student under the joint supervision of Arnaud GUILLIN and Pierre MONMARCHÉ at LJLL, Sorbonne Université, Paris, France.
• Title: Systems of particles in (singular) interaction: long time behavior and propagation of chaos.
• Defended June 20th, 2023
• Referees: François Delarue, Martin Hairer.
• Jury: Thierry Bodineau, Nicolas Fournier, Sylvia Serfaty, Sylvie Méléard (Committee president).
• 2019-2020: MSc Year 2: Probabilities and Random Models, Sorbonne Université, Paris, France.
• 2016-2020: Ingénieur Polytechnicien Program (Master of Engineering, Science and Technology), École Polytechnique, Palaiseau, France.

PREPRINTS AND PUBLICATIONS

1. On uniform in time propagation of chaos in metastable cases: the Curie-Weiss model, with Lucas Journel, 2025. Preprint. (arxiv)

1. HMC and underdamped Langevin united in the unadjusted convex smooth case, with Nicolaï Gouraud, Adrien Majka and Pierre Monmarché, SIAM/ASA Journal on Uncertainty Quantification, Vol 13, Iss. 1, 2025. article. (Former versions: arxiv)
2. Some remarks on the effect of the Random Batch Method on phase transition, with Arnaud Guillin and Pierre Monmarché, Stochastic Processes and their Applications, Volume 179, 2025. article. (Former version: arxiv , HAL). Python codes available here.
3. A note on uniform in time mean-field limit in graphs, with Christophe Poquet, ALEA Latin American Journal of Probability and Mathematical Statistics, 2024. article. (Former versions: arxiv)
4. Uniform in time propagation of chaos for the 2D vortex model and other singular stochastic systems, with Arnaud Guillin and Pierre Monmarché, Journal of the European Mathematical Society, 2024, pp. 1–28. article. (Former versions: arxiv, HAL)
Small correction: In the change of variable y->x-y, there is no negative sign appearing on pages 7,8,10 and 22. This does not modify further calculations.
5. Propagation of chaos in mean field networks of FitzHugh-Nagumo neurons, with Laetitia Colombani, Mathematical Neurosciences and Applications, Volume 3, 2023. article. (Former versions: arxiv, HAL)
6. On systems of particles in singular repulsive interaction in dimension one: log and Riesz gas, with Arnaud Guillin and Pierre Monmarché, Journal de l’École polytechnique — Mathématiques, Tome 10, 2023, pp. 867-916. article. (Former versions: arxiv, HAL)
7. Convergence rates for the Vlasov-Fokker-Planck equation and uniform in time propagation of chaos in non convex cases, with Arnaud Guillin and Pierre Monmarché, Electronic Journal of Probability, Vol. 27, paper no. 124, 1-44, 2022. article. (Former versions: arxiv, HAL)

1. Uniform in time mean field limits for 1D Riesz gases, Séminaire Laurent Schwartz — EDP et applications (2023-2024), Exposé no. 11. article
2. Some recent results on propagation of chaos and mean-field limits, in Classical and Quantum Mechanical Models of Many-Particle Systems, Oberwolfach Rep. 20 (2023), no. 3, pp. 2179–2246. article.
3. Recent progress on limit theorems for large stochastic particle systems, with Max Fathi, Angeliki Menegaki, Pierre Monmarché, Julien Reygner, and Milica Tomašević, ESAIM: Proceedings and surveys, December 2023, Vol. 75, p. 2-23. article. (Former versions: HAL)

• Systems of particles in (singular) interaction: long time behavior and propagation of chaos, defended June 20th, 2023. (Manuscript).

RECORDED TALKS

• Quelques résultats récents de propagation du chaos et limite de champ moyen, for the Séminaire de Mathématiques Appliquées du Collège de France, June 2nd, 2023 (Paris, France). (Video)
• Proving propagation of chaos and mean-field limits, for the Seed seminar of mathematics and physics, January 17, 2024 (Paris, France). (Video)

TALKS

• 2025:
  • Upcoming 18/06: Workshop ANR Conviviality (Lyon, France).
  • Upcoming 02-06/06: Workshop "Longtime Behavior of Stochastic Processes" (Clermont-Ferrand, France).
  • Upcoming 13/05: Séminaire de probabilités de l'I2M (Marseille, France).
  • Séminaire de Probabilités CMAP (Palaiseau, France).
  • Séminaire de Probabilités commun ICJ/UMPA (Lyon, France).
  • Séminaire MAD-Stat, Toulouse School of Economics (Toulouse, France).
• 2024:
  • Séminaire de probabilités et mathématiques financières, LaMME (Evry, France).
  • Imperial College, Applied PDEs Seminar (London, UK).
  • Meanlysm: Round Meanfield III, new phenomenology (Roma, Italy).
  • Journées MAS, parallel session "Functional inequalities" (Poitiers, France).
  • Seminaire de probabilités et statistiques, LMO (Orsay, France).
  • Journées Jeunes Edpistes en France (Toulouse, France).
  • Séminaire Laurent Schwartz (Bures-sur-Yvette, France).
  • Seed seminar of mathematics and physics (Paris, France).
• 2023:
  • Workshop Journée équations d'évolution (Bures-sur-Yvette, France).
  • Oberwolfach Workshop Classical and Quantum Mechanical Models of Many-Particle Systems (Oberwolfach-Walke, Germany).
  • Mean Field Models Summer School (Rennes, France).
  • Séminaire de Mathématiques Appliquées du Collège de France (Paris, France).
  • Markov Working Group of Jussieu (Paris, France).
• 2022:
  • ANR workshop Journées EFI 2022 (Lyon, France).
  • Groupe de Travail Modélisation Stochastique of LPSM (Paris, France).
  • Summer School: Global Sensivivity Analysis and Poincaré inequalities (Toulouse, France).
  • 4th Workshop of ANR QuAMProcs (Paris, France).
  • PhD students' Working Group of LPSM (Paris, France).
  • PhD students' Working Group of LJLL (Paris, France).
• 2021:
  • ANR workshop Journées EFI 2021 (Paris, France).
  • 10ième Biennale Française des Mathématiques Appliquées et Industrielles (La Grande Motte, France).
  • Mini-course for the PDE Working Group of LJLL (Paris, France). (Notes)

TEACHING

• 2020-2023: BSc (Year 3, Sorbonne Université) LU3MA232: Numerical Analysis. TD (24h/year) + TP in Python (12h/year) + Correction.
• 2020-2022: BSc (Year 3, Sorbonne Université) LU3MA290: Probability II. TD (36h/year) + Correction.

OTHER SCIENTIFIC ACTIVITIES

• Annales de l’Institut Henri Poincaré (x3),
• Annals of Applied Probability,
• Communications in Mathematical Sciences,
• Journal of Evolution Equations,
• Mathematische Annalen,
• Mathematical Modelling and Numerical Analysis,
• Stochastics and Partial Differential Equations: Analysis and Computations,
• Stochastic Processes and their Applications.