Page 1 Next

Displaying 1 – 20 of 23

Showing per page

Déformations d’algèbres associées à une variété symplectique (les * ν -produits)

André Lichnerowicz (1982)

Annales de l'institut Fourier

Fondements de la théorie des * v -produits. Notion de * v -produit de Vey; tout * v -produit est équivalent à un * v -produit de Vey. Sur toute variété symplectique paracompacte ( W , F ) telle que b 3 ( W ) = 0 , il existe des * v -produits de Vey. Caractérisation des algèbres de Lie engendrées par antisymétrisation d’un * v -produit (éventuellement faible); ce sont à une équivalence près, les algèbres de Lie de Vey.On considère les variétés symplectiques ( W , F ) sur lesquelles opère, par symplectomorphismes, un groupe de Lie G . Si ( W , F ) admet...

Deformations of structures, embedding of a Riemannian manifold in a Kählerian one and geometric antigravitation

Alexander A. Ermolitski (2007)

Banach Center Publications

Tubular neighborhoods play an important role in modern differential topology. The main aim of the paper is to apply these constructions to geometry of structures on Riemannian manifolds. Deformations of tensor structures on a normal tubular neighborhood of a submanifold in a Riemannian manifold are considered in section 1. In section 2, this approach is used to obtain a Kählerian structure on the corresponding normal tubular neighborhood of the null section in the tangent bundle TM of a smooth manifold...

Distinguished connections on ( J 2 = ± 1 ) -metric manifolds

Fernando Etayo, Rafael Santamaría (2016)

Archivum Mathematicum

We study several linear connections (the first canonical, the Chern, the well adapted, the Levi Civita, the Kobayashi-Nomizu, the Yano, the Bismut and those with totally skew-symmetric torsion) which can be defined on the four geometric types of ( J 2 = ± 1 ) -metric manifolds. We characterize when such a connection is adapted to the structure, and obtain a lot of results about coincidence among connections. We prove that the first canonical and the well adapted connections define a one-parameter family of adapted...

Dolbeault homotopy theory and compact nilmanifolds

L. Cordero, M. Fernández, A. Gray, L. Ugarte (1998)

Banach Center Publications

In this paper we study the degeneration of both the cohomology and the cohomotopy Frölicher spectral sequences in a special class of complex manifolds, namely the class of compact nilmanifolds endowed with a nilpotent complex structure. Whereas the cohomotopy spectral sequence is always degenerate for such a manifold, there exist many nilpotent complex structures on compact nilmanifolds for which the classical Frölicher spectral sequence does not collapse even at the second term.

Currently displaying 1 – 20 of 23

Page 1 Next