Déformations des algèbres de Lie locales et analogue du théorème d'algébricité de Carles.
Déformations différentielles à coefficients constants et produits de Moyal généralisés
Deformations of CR-structures on a real Lie-algebra
Sia unalgebra di Lie e (p, J) una sua struttura di Cauchy-Riemann, vale a dire J è una struttura complessa integrabile del sottospazio vettoriale p. Come è stato fatto per il caso delle strutture complesse, cfr. [GT], introduciamo il concetto di deformazione di una struttura CR. Per mezzo dei gruppi di coomologia vengono provati risultati di rigidità. In particolare ogni struttura di Lie- CR che è semisemplice è rigida. Alcuni esempi chiariscono le soluzioni particolari esposte.
Deformations of Lie brackets: cohomological aspects
We introduce a new cohomology for Lie algebroids, and prove that it provides a differential graded Lie algebra which “controls” deformations of the structure bracket of the algebroid.
Degree one cohomology for the Lie algebras of derivations.
Dérivations et déformations de certaines algèbres de Lie infinies classiques
Des espaces homogènes à la résolution de Koszul
Cette note évoque les premiers travaux de J.-L. Koszul (1947-1950) en les replaçant dans leur cadre historique et retrace en particulier le chemin qui a conduit Koszul à la résolution qui porte son nom.
Different methods for the study of obstructions in the schemes of Jacobi
In this paper the problem of obstructions in Lie algebra deformations is studied from four different points of view. First, we illustrate the method of local ring, an alternative to Gerstenhaber’s method for Lie deformations. We draw parallels between both methods showing that an obstruction class corresponds to a nilpotent local parameter of a versal deformation of the law in the scheme of Jacobi. Then, an elimination process in the global ring, which defines the scheme, allows us to obtain nilpotent...
Effacement et déformation
Soit un corps de caractéristique zéro. La variété des algèbres de Lie sur n’est pas réduite en général. Si est une algèbre de Lie dimension finie sur l’application quadratique se factorise à travers le sous-espace des trois-classes de cohomologie effaçables.
Explicit expression of Cartan’s connection for Levi-nondegenerate 3-manifolds in complex surfaces, and identification of the Heisenberg sphere
We study effectively the Cartan geometry of Levi-nondegenerate C 6-smooth hypersurfaces M 3 in ℂ2. Notably, we present the so-called curvature function of a related Tanaka-type normal connection explicitly in terms of a graphing function for M, which is the initial, single available datum. Vanishing of this curvature function then characterizes explicitly the local biholomorphic equivalence of such M 3 ⊂ ℂ2 to the Heisenberg sphere ℍ3, such M’s being necessarily real analytic.
Explicit formulae for cocycles of holomorphic vector fields with values in densities.
Extension functors of modular Lie algebras.
Extensions Between Generalized Verma Modules: The Hermitian Symmetric Cases.
Extensions of super Lie algebras.
Extensions of symplectic groupoids and quantization.
Formal deformations and principal series representations of and
In this note, we study formal deformations of derived representations of the principal series representations of . In particular, we recover all the representations of the derived principal series by deforming one of them. Similar results are also obtained for .
Forme canonique sur le dual du fibré transverse
Formes harmoniques et cohomologie relative des algèbres de Lie.
Formes harmoniques et cohomologie relative des algèbres de Lie
Four dimensional symplectic Lie algebras.