17 juin 2024 @ 14:00 – 15:00 – Voisin’s work, which constructs a series of K-trivial varieties from cubic hypersurfaces, and self-rational maps on them, called the Voisin maps, will be the focus here. Notable among these is the Fano variety of lines of a cubic fourfold, a dimension 4 hyper-Kähler manifold. The Voisin map in this case has been extensively studied. We’ll […]
14 juin 2024 @ 11:00 – 12:00 – We give a light talk on optimality of shapes in geometry and physics. First, we recollect classical geometric results that the disk has the largest area (respectively, the smallest perimeter) among all domains of a given perimeter (respectively, area). Second, we recall that the circular drum has the lowest fundamental tone among all drums of […]
13 juin 2024 @ 15:45 – 16:45 – We consider the problem of quantizing the positive nilradical of a complex semisimple Lie algebra of finite rank, together with a certain fixed direct sum decomposition. The decompositions we consider are in one-to-one correspondence with total orders on the simple roots, and exhibit the nilradical as a direct sum of graded modules for appropriate Levi […]
13 juin 2024 @ 14:30 – 15:30 – À chaque polynôme unitaire sans facteur carré
13 juin 2024 @ 14:15 – 15:15 – In this talk we will present some results concerning the Fried’s conjecture, i.e., the relation of the twisted dynamical zeta function of Ruelle at zero and spectral invariants for a hyperbolic manifold X. In particular, we consider the twisted Ruelle zeta function twisted by an arbitrary representation of the lattice. We study then its relation to the Ray-Singer norm of the refined analytic torsion. The […]
10 juin 2024 @ 14:00 – 15:00 – Title: Random walks on affine buildings of type \tilde{A}_2. Summary: Let
5 juin 2024 @ 10:45 – 11:45 – We will explain the following meme : the connection between Hopf fibration, homotopy groups, cobordism, and algebraic K-theory. And why the formula « 0=1-1=-1+1=0 » explains everything.
4 juin 2024 @ 14:15 – 15:15 – (Joint work with G. Liu and S. Mehdi) For the last decades, representation theory of Lie groups and algebras has been a very active research topic with a multitude of ramifications and applications. Since the work, in the 1970’s, of Parthasarathy and Atiyah-Schmid, Dirac operators have become efficient tools to describe and classify the unitary […]
4 juin 2024 @ 13:15 – 14:15 – La bibliothèque vous propose un temps d’échange sur HAL au moment du café pour discuter de vos problématiques et besoins sur HAL ainsi que des actualités de la plateforme. Le prochain café HAL aura lieu mardi 4 juin à la salle café à partir de 13h15
3 juin 2024 @ 14:00 – 16:00 – Support cohomologique des modules basculants pour les groupes algébriques réductifs Il est connu depuis les années 1970 que de nombreuses informations concernant la théorie des représentations des groupes algébriques réductifs sur des corps de caractéristique positive peuvent s’exprimer en terme de la combinatoire du groupe de Weyl affine associé. Une forme subtile de cette relation […]