ESPCI web site
Séminaire Café (Interne)
Il s’agit d’un exposé assez court (20 min) et assez informel.
Prière aux conférencier·ère·s de ne jamais dépasser 30 min et de vérifier la compatibilité avec le projecteur avant le séminaire.
Les séminaires ont lieu les jeudis après la réunion du laboratoire qui débute à 13h30 dans la bibliothèque du labo sur le campus Jussieu, Barre Cassan, Bât A, 1er étage.
Pour suggérer un titre et envoyer un abstract, contacter 
et 
.
Coffee seminars are supposed to be short and informal presentations (20 min).
Please never last longer than 30 min and check the compatibility of the projector with your computer before the seminar.
Location : Campus Jussieu, Barre Cassan, Bât A, 1er étage
7 quai Saint Bernard
75005 Paris
To suggest a title or send an abstract, please contact and .
| 20 novembre | Marine Aulnette - PMMH Transport of microparticles in a 3D vortex flow |
| 27 novembre | Marc Lagoin - Postdoc au LOMA, Bordeaux Thermodynamics of Nonequilibrium Systems, from Maxwell Demons to Active Microswimmers in Confined Flows Many physical systems can be described using a few coarse variables, ignoring most microscopic details. This idea, formalized in Langevin’s theory of Brownian motion [3], allows us to understand how fluctuations and dissipation produce predictable behaviours even in systems far from equilibrium.In this talk, I will present two experiments that illustrate this approach. First, in a driven granular gas, we built a macroscopic version of a Feynman-type ratchet [4,7] and measured how fluctuations can be rectified to produce motion. This work is described in Ref. [2] and provides a simple experimental test of stochastic models.Second, we studied Chlamydomonas reinhardtii microswimmers in oscillatory Poiseuille flows. By tracking their motion, we measured their long-time dispersion and interpreted it using a coarse-grained Brownian-particle description [8]. This leads to an active version of the classical Taylor–Aris dispersion [5,6], as shown in Ref. [1]. These two studies show that simple stochastic descriptions can help in understanding the behaviour of nonequilibrium systems, from macroscopic mechanical devices to suspensions of active microorganisms. [1] M.Lagoin, J. Lacherez, G. de Tournemire, A. Badr, Y. Amarouchene, A. Allard, and T. Salez, Enhanced dispersion of active microswimmers in confined flows, PNAS (2025) ; arXiv:2507.08369. [2] M. Lagoin, C. Crauste-Thibierge, A. Naert, A human-scale Brownian ratchet, Phys. Rev. Lett. (2022) ; HAL : hal-03650213. [3] P. Langevin, Sur la théorie du mouvement brownien, C. R. Acad. Sci. (1908). [4] R. P. Feynman, The Feynman Lectures on Physics, Vol. I, Ch. 46 : Ratchet and Pawl (1964). [5] G. I. Taylor, Dispersion of soluble matter in solvent flowing slowly through a tube, Proc. R. Soc. A (1953). [6] R. Aris, On the dispersion of a solute in a fluid flowing through a tube, Proc. R. Soc. A (1956). [7] M. von Smoluchowski, early works on fluctuation-induced transport (1912). [8] H. Risken, The Fokker–Planck Equation : Methods of Solution and Applications. |
| 4 décembre | PhD Defense : Jeanne Moscatelli |
| 11 décembre | Présentations des 2ème année - PMMH Widad Mesbahi & Litan Wang |
