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Legendrian dual surfaces in hyperbolic 3-space

Kentaro Saji, Handan Yıldırım (2015)

Annales Polonici Mathematici

We consider surfaces in hyperbolic 3-space and their duals. We study flat dual surfaces in hyperbolic 3-space by using extended Legendrian dualities between pseudo-hyperspheres in Lorentz-Minkowski 4-space. We define the flatness of a surface in hyperbolic 3-space by the degeneracy of its dual, which is similar to the case of the Gauss map of a surface in Euclidean 3-space. Such surfaces are a kind of ruled surfaces. Moreover, we investigate the singularities of these surfaces and the dualities...

Legendrian graphs and quasipositive diagrams

Sebastian Baader, Masaharu Ishikawa (2009)

Annales de la faculté des sciences de Toulouse Mathématiques

In this paper we clarify the relationship between ribbon surfaces of Legendrian graphs and quasipositive diagrams by using certain fence diagrams. As an application, we give an alternative proof of a theorem concerning a relationship between quasipositive fiber surfaces and contact structures on S 3 . We also answer a question of L. Rudolph concerning moves of quasipositive diagrams.

Lemme de Moser feuilleté et clasifications des variétés de Poisson régulières.

G. Héctor, E. Macías, M. Saralegui (1989)

Publicacions Matemàtiques

Regular Poisson structures with fixed characteristic foliation F are described by means of foliated symplectic forms. Associated to each of these structures, there is a class in the second group of foliated cohomology H2(F). Using a foliated version of Moser's lemma, we study the isotopy classes of these structures in relation with their cohomology class. Explicit examples, with dim F = 2, are described.

Length minimizing Hamiltonian paths for symplectically aspherical manifolds

Ely Kerman, François Lalonde (2003)

Annales de l’institut Fourier

In this note we consider the length minimizing properties of Hamiltonian paths generated by quasi-autonomous Hamiltonians on symplectically aspherical manifolds. Motivated by the work of Polterovich and Schwarz, we study the role, in the Floer complex of the generating Hamiltonian, of the global extrema which remain fixed as the time varies. Our main result determines a natural condition which implies that the corresponding path minimizes the positive Hofer length. We use this to prove that a quasi-autonomous Hamiltonian...

Length of curves on Lip manifolds

Giuseppe De Cecco, Giuliana Palmieri (1990)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

In this paper the length of a curve on a Lipschitz Riemannian manifold is defined. It is shown that the above definition is consistent with the definition of the geodesic distance already introduced by the authors, both in a geometrical and analytical way.

Lepage forms theory applied

Michal Lenc, Jana Musilová, Lenka Czudková (2009)

Archivum Mathematicum

In the presented paper we apply the theory of Lepage forms on jet prolongations of fibred manifold with one-dimensional base to the relativistic mechanics. Using this geometrical theory, we obtain and discuss some well-known conservation laws in their general form and apply them to a concrete physical example.

Les connexions hypergéométriques et le théorème de linéarité de T. Terasoma

Fayçal Maaref (1997)

Annales de l'institut Fourier

Cet article a pour but de calculer les coefficients du caractère du produit alterné des déterminants des connexions de Gauss–Manin associées à une famille de p polynômes sur C n . Nous généralisons et précisons certains résultats de T. Terasoma (Inv. Math., 1992). L’idée de ce travail est de considérer la structure mixte donnée par l’action des translations entières sur les exposants s 1 , ... , s p sur le déterminant de l’image directe de 𝒪 f 1 s 1 ... f p s p et celle de 𝒟 -module.

Les géométries de Hilbert sont à géométrie locale bornée

Bruno Colbois, Constantin Vernicos (2007)

Annales de l’institut Fourier

On montre que la géométrie de Hilbert d’un domaine convexe de n est à géométrie locale bornée c-à-d que pour un rayon fixé, toutes les boules sont bilipschitz à un domaine de n euclidien. On en déduit que si la géométrie de Hilbert est hyperbolique au sens de Gromov, alors le bas de son spectre est strictement positif. On donne un contre-exemple en dimension trois qui montre que la réciproque n’est pas vraie pour les géométries de Hilbert non planes.

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