Yoan Tardy
Le Tuyet Nhi Pham
March 2026, Hanoi
I spent a week in March 2026 in Hanoi, Vietnam, following an invitation from my PhD supervisor, Gaël Raoul, and had the opportunity to participate in the workshop Stochastic Particle Systems: From Biology and Machine Learning at the Vietnam Institute for Advanced Study in Mathematics (VIASM).
The workshop brought together researchers working on stochastic particle systems, stochastic differential equations, mean-field limits, and diffusion-based methods in machine learning, providing a stimulating environment for scientific exchange between researchers from France and Vietnam. During the workshop, I had the pleasure of engaging in insightful discussions with Yoan Tardy (CMAP, École Polytechnique), Prof. Hoang Long Ngo (Hanoi National University of Education), Prof. Tu-Bao Ho, as well as other researchers and students. I also gave a minicourse entitled Introduction to Stochastic Processes, where I introduced fundamental concepts and tools in the theory of stochastic processes, and discussed their connections with modern machine learning. In particular, I presented an introduction to score-based generative models and discussed my recent work on Convergence Guarantees of Discrete Diffusion Models, providing an opportunity to exchange ideas on the mathematical foundations of diffusion-based generative modeling. Beyond the scientific programme, this mission was a valuable opportunity to connect with students, young researchers, and colleagues in Vietnam, and to strengthen interactions between the mathematical communities in France and Vietnam.
I am very grateful to Gaël Raoul for the invitation and to the IRL-FVMA and VIASM for their financial support, as well as to all the organizers, speakers, researchers, and students who contributed to making this stay scientifically enriching and enjoyable.
Le Tuyet Nhi Pham
Lionel Schwartz
March 2026
I spent the month of March 2026 at VIASM Hanoi.
During this period In made a short 4 days visit in Hué, in order to
complete the corrections of a joint Notes aux Comptes Rendus with
Nguyen dang Ho Hai. This note is entitled “(Brown-Gitler spectra and
regular representation of (Z/2)^n and is going to appear in a foredooming issue of Comptes Rendus. It competes, on a more geometric side, older works with Hai on one hand and Bourguiba, Lannes and Zarati on the other hand. During this visit I made a talk for a wide audience on free groups, free Lie algebras and Magnus’ meth
In Hanoi with Le Minh Ha and Pham Van Tuan we organized a Workshop in Memory of Phạm Anh Minh. Speakers where : David J. Green, University of Jena, Germany (online), Huỳnh Mùi, ME Primary School, Hanoi, Vietnam, Nguyễn Đặng Hồ Hải, Huế University, Vietnam, Nguyễn Hữu Việt Hưng, Thăng Long University, Vietnam, Peter Symonds, University of Manchester, UK (online)
We organized also a sprig school on functor theory and homotopy groups. There were 3 mini-courses by Pham Van Tuan, me and Aurélien Djament (online) details are on
https://viasm.edu.vn/hdkh/SSATA?userkey=workshop
I gave 4 talks on simplicial topology, Curtis’ spectral sequence and free Lie functors.
Christian Ausoni, Sorbonne Paris North University, France; (online)
Emmanuel Farjoun, Hebrew University of Jerusalem, Israel;(online)
Huỳnh Mùi, ME Primary School, Hanoi, Vietnam;
Sergei Ivanov, Beijing Institute of Mathematical Sciences and
Applications, China; (online)
Lê Quý Thường, VNU University of Science, Hanoi, Vietnam;
Mai Quang Huy, FPT University, Hanoi, Vietnam;
Nguyễn Thế Cường, VNU University of Science, Hanoi, Vietnam;
Nguyễn Đặng Hồ Hải, Huế University, Vietnam;
Nguyễn Đức Khánh, VIASM, Vietnam;
Lionel Schwartz
Piotr Graczyk
Bac Dang
June 2026
I gave a series of lectures on Convex Geometry and Algebraic Geometry, hosted by the Vietnam Institute for Advanced Study in Mathematics (VIASM) in June 2026.
The lectures aimed to introduce graduate students and researchers to several remarkable connections between convex geometry and algebraic geometry. The course required only basic knowledge of algebra and measure theory, and no prior knowledge of algebraic geometry was assumed.
A central theme of the lectures was the correspondence between constructions in local algebra and convex geometry. In particular, the course explored the relationship between Hilbert–Samuel multiplicities and covolumes of convex sets, as well as their mixed versions. This led to a broader discussion of the analogies between local rings and cones, primary ideals and co-convex sets, and mixed multiplicities and mixed covolumes.
The lectures began with an introduction to Hilbert–Samuel multiplicity and the construction of the normal cone, followed by a discussion of polynomiality phenomena associated with several ideals. The second part of the course developed the convex-geometric framework of co-convex sets, covolumes, surface area measures, and support functions.
Further topics included three-body inequalities for mixed covolumes, Fourier-analytic methods in dimension two, and the theorem of Kaveh–Khovanskii relating monomial ideals and Newton polygons to convex geometry. The lectures also discussed higher-dimensional extensions and examples involving intersection theory, the Hodge index theorem, and Teissier-type inequalities.
The lectures brought together approximately 4–5 graduate students, together with active researchers in Vietnam, creating a small and interactive setting for discussions and scientific exchange.
The event was organized by Thang Nguyen and hosted at VIASM, with financial support from both the CNRS and Université Paris-Saclay. It provided an opportunity to strengthen scientific exchanges between researchers in France and Vietnam and to foster further interactions in convex geometry, algebraic geometry, and related areas.
Bac Dang
Takuji Kashiwabara
July 2026
I was invited to spend half month at VIASM on July 2026. Professors Phan Hoang Chon (Saigon) Nguyen Dang Ho Hai (Hue) and I started collaborating on the question of the invariants of the Morava K-theory of the classifying space of the elementary abelian groups under the action of general linear groups, but it was while my stay that we made a possible breakthrough, on which I gave a seminar talk.
I also enjoyed an occasion to give a talk students’s reading seminar, mini course on
cobordism theory. I enjoyed very much the research environment provided by VIASM as well as nice accommodation, I would like to express my thanks to VIASM/IRCP as well as IRL/FVMA for financial support, VIASM stuff for all the help,and my colleagues for exciting exchanges.
Takuji Kashiwabara
Gérard Besson