-partitions and a multi-parameter Klyachko idempotent.
Pour tout groupe de Lie nilpotent réel connexe et simplement connexe, on construit une stratification du dual de l’algèbre de Lie, et on paramètre chaque strate au moyen d’un triplet de fonctions rationnelles à valeurs vectorielles; les valeurs de caractérisent les orbites de la strate et pour chacune de ces orbites, le couple constitue une carte de Darboux.
Let be a preprojective algebra of type , and let be the corresponding semisimple simply connected complex algebraic group. We study rigid modules in subcategories for an injective -module, and we introduce a mutation operation between complete rigid modules in . This yields cluster algebra structures on the coordinate rings of the partial flag varieties attached to .
A methodical analysis of the research related to the article, “Sur les groupes continus”, of Henri Poincaré reveals many historical misconceptions and inaccuracies regarding his contribution to Lie theory. A thorough reading of this article confirms the priority of his discovery of many important concepts, especially that of the universal enveloping algebra of a Lie algebra over the real or complex field, and the canonical map (symmetrization) of the symmetric algebra onto the universal enveloping...