Analysis of the Navier–Stokes equations: existence and regularity

The Navier–Stokes equations, at the heart of fluid mechanics, represent a fundamental challenge in contemporary mathematical analysis. Modeling the motion of incompressible fluids, these partial differential equations form the theoretical basis of fluid dynamics. Their richness and complexity lie in particular in the study of the existence and regularity of their solutions. Despite having been … Read more

Optimization on manifolds: applied Riemannian geometry

Riemannian geometry, a pioneering branch of differential geometry, provides a powerful framework for extending classical optimization methods beyond Euclidean spaces. At a time when big data is becoming increasingly complex, modeling on nonlinear structures such as manifolds offers mathematical tools suited to capturing this inherent complexity. Optimization on manifolds has thus emerged as a field … Read more

The theory of quadratic forms: algebra and geometry

The theory of quadratic forms is a fundamental pillar at the intersection of algebra and geometry. It offers a powerful perspective for deciphering the properties of homogeneous polynomials of degree two, as well as their connections to the structure of vector spaces. Long confined to abstract mathematical treatises, this discipline now permeates a variety of … Read more

The Analysis of Complex Networks: Topology and Dynamics

Complex networks are one of the most dynamic and multidisciplinary fields of contemporary scientific research. Their study, which brings together advanced mathematics, computer science, physics, and biology, offers valuable insight into the topology and dynamics found in many real-world systems. From social networks and biological interactions to technical infrastructure and information systems, the analysis of … Read more

Pseudo-spectral methods: approximation by global polynomials

Used extensively in the numerical solution of differential equations, pseudo-spectral methods combine the power of global polynomials with spectral approximation techniques to deliver remarkable accuracy. In 2025, they continue to dominate the field of numerical methods thanks to their ability to handle complex problems with optimized computational costs. Based on polynomial approximation at so-called collocation … Read more

The Geometry of Fano Varieties: Positivity and Classification

The geometry of Fano varieties represents an indispensable cornerstone of contemporary algebraic geometry, bringing to light fundamental notions such as the positivity of line bundles and the detailed study of complex structures. These varieties, characterized by their positive curvature, embody a rich research subject that connects topology, geometry, and algebra. In 2025, their in-depth classification … Read more

Multiresolution analysis: decomposition and reconstruction

Multiresolution analysis is a fundamental concept in signal and image processing, making it possible to examine a signal at different resolution scales. This method originated in the pioneering work of Meyer and Mallat, who laid the foundations for an effective technique to decompose a signal into elementary components and then reconstruct it with remarkable precision. … Read more

Semigroup Theory: Evolution and Generators

Semigroup theory has established itself as an indispensable cornerstone in the study of dynamic phenomena and differential equations. Through its abstract approach rooted in algebra and functional analysis, this theory offers a powerful framework for describing the evolution of complex systems. Since its foundations were laid, it has grown richer by incorporating notions of operator … Read more

Functional Data Analysis: Statistics on Curves

In the field of statistics, functional data analysis is revolutionizing the way information measured over time or across a continuum is processed. Unlike traditional approaches centered on point data or vectors, this discipline studies data in the form of complete curves, thereby modeling dynamic and complex phenomena. Data visualization, combined with nonparametric methods and curve-smoothing … Read more

The geometry of quotient spaces: group actions

The geometry of quotient spaces imposes itself as a major discipline at the intersection of algebra, topology, and differential geometry. At the heart of this theory, group actions allow us to explore the structure of underlying sets through their symmetry, revealing the mechanisms by which complex spaces simplify into quotient spaces. This dynamic, often illustrated … Read more