Concept
Groupe de Lie
Publications associées (139)
Multiplicity-free Representations of Algebraic Groups
Donna Testerman, Martin W. Liebeck
Let K be an algebraically closed field of characteristic zero, and let G be a connected reductive algebraic group over K. We address the problem of classifying triples (G, H, V ), where H is a proper connected subgroup of G, and V is a finitedimensional ir ...
Amer Mathematical Soc2024Touch and Closeness in Naturally Organized Activities
Countless aspects of touch and closeness have been questioned in an unprecedented way during the recent Covid epidemic. Social practices as banal as greetings were both reflexively and practically challenged and sometimes deeply altered, resulting in painf ...
2024Lie groups in the symmetric group: Reducing Ulam's problem to the simple case
Ulam asked whether all Lie groups can be represented faithfully on a countable set. We establish a reduction of Ulam's problem to the case of simple Lie groups. In particular, we solve the problem for all solvable Lie groups and more generally Lie groups w ...
San Diego2023Unlikely intersections on the p-adic formal ball
We investigate generalizations along the lines of the Mordell-Lang conjecture of the author's p-adic formal Manin-Mumford results for n-dimensional p-divisible formal groups F. In particular, given a finitely generated subgroup (sic) of F(Q(p)) and a close ...
SPRINGER INT PUBL AG2023Duality and bicrystals on infinite binary matrices
The set of finite binary matrices of a given size is known to carry a finite type AA bicrystal structure. We first review this classical construction, explain how it yields a short proof of the equality between Kostka polynomials and one-dimensional sums t ...
2023Lie groups as permutation groups: Ulam's problem in the nilpotent case
Ulam asked whether every connected Lie group can be represented on a countable structure. This is known in the linear case. We establish it for the first family of non-linear groups, namely in the nilpotent case. Further context is discussed to illustrate ...
WALTER DE GRUYTER GMBH2022A b-symplectic slice theorem
In this article, motivated by the study of symplectic structures on manifolds with boundary and the systematic study of b-symplectic manifolds started in Guillemin, Miranda, and Pires Adv. Math. 264 (2014), 864-896, we prove a slice theorem for Lie group a ...
WILEY2022Effect of Different Communication Affordances on the Emergence of Collaboration Strategies in an Online Multiplayer Game
Pierre Dillenbourg, Barbara Bruno, Hala Khodr, Aditi Kothiyal
In a group, the collective dynamics is governed by the inter- actions between individuals, which can manifest differently depending on the available means of communication. In this paper, we compare 3 conditions of communication affordances (global chat, l ...
Springer2022The Cen A galaxy group: Dynamical mass and missing baryons
The nearby elliptical galaxy Centaurus A (Cen A) is surrounded by a flattened system of dwarf satellite galaxies with coherent motions. Using a novel Bayesian approach, we measured the mean rotation velocity nu(rot) and velocity dispersion sigma(int) of th ...
EDP SCIENCES S A2022Fourier non-uniqueness sets from totally real number fields
Let K be a totally real number field of degree n >= 2. The inverse different of K gives rise to a lattice in Rn. We prove that the space of Schwartz Fourier eigenfunctions on R-n which vanish on the "component-wise square root" of this lattice, is infinite ...
EUROPEAN MATHEMATICAL SOC-EMS2022