On commencera par rappeler la théorie de Doeblin pour les systèmes conservatifs (semi-groupes de Markov) ainsi que le théorème de Harris qui la généralise via l’utilisation d’une fonction de Lyapunov. On présentera ensuite une méthode de renormalisation qui permet l’extension
L'anneau des caractères (complexes) d'un groupe G est équipé d'une filtration dite de Grothendieck, induite par les puissances extérieures des représentations de G. Peut-on calculer explicitement l'anneau gradué associé à cette filtration ? Quels liens y a-t-il entre l'anneau gradué
Pólya urns are urns where at each unit of time a ball is drawn uniformly at random and is replaced by some other balls according to its colour. We introduce a more general model : The replacement rule depends on
This talk summarizes joint works by the speaker and Anne-Sophie Bonnet-Ben Dhia, Lucas Chesnel, Camille Carvalho and Juan-Pablo Borthagaray on how to solve problems with discontinuous, sign-changing coefficients. In electromagnetic theory, the effective response of specifically designed materials is modeled
Boundary regression models naturally arise in many applications for instance when analysing auctions or records but also in production frontiers and image analysis. Before fitting a regression model it is very common to transform the response variable to gain effciency
We prove that the set of Lipschitz functions with the property of having a maximal Clarke subdifferential at every point contains a linear subspace of uncountable dimension. Our approach is constructive. In particular, in strong contrast to a previous result
In a series of recent papers, Chiodo, Farkas and Ludwig carried out a deep analysis of the singular locus of the moduli space of stable (twisted) curves with an $\ell$-torsion line bundle. This opens the way to a computation of
Les modèles de mutations décrivent le processus d'apparitions rares et aléatoires de mutations au cours de la croissance d'une population de cellules. Les échantillons obtenus sont constitués de nombres finaux de cellules mutantes, qui peuvent être couplés avec des nombres
The HiMQ-3 signature scheme is a very efficient multivariate signature scheme and was one of the first round candidates of the NIST post-quantum standardization process. In this talk we present a new attack against HiMQ-3, the so called singularity attack.
The generalized birthday problem, or k-xor problem, has many applications in cryptography. Interestingly, there is a gap between its provable query complexity and its best known time complexity, obtained with Wagner’s algorithm. Quantum algorithms for this problem have been studied
