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Some examples of essential laminations in 3-manifolds

Allen Hatcher (1992)

Annales de l'institut Fourier

Families of codimension-one foliations and laminations are constructed in certain 3-manifolds, with the property that their transverse intersection with the boundary torus of the manifold consists of parallel curves whose slope varies continuously with certain parameters in the construction. The 3-manifolds are 2-bridge knot complements and punctured-torus bundles.

Some examples of nonsingular Morse-Smale vector fields on S 3

F. Wesley Wilson Jr (1977)

Annales de l'institut Fourier

One wonders or not whether it is possible to determine the homotopy class of a vector field by examining some algebraic invariants associated with its qualitative behavior. In this paper, we investigate the algebraic invariants which are usually associated with the periodic solutions of non-singular Morse-Smale vector fields on the 3-sphere. We exhibit some examples for which there appears to be no correlation between the algebraic invariants of the periodic solutions and the homotopy classes of...

Some examples of vector fields on the 3-sphere

F. Wesley Wilson (1970)

Annales de l'institut Fourier

Let S 3 denote the set of points with modulus one in euclidean 4-space R 4  ; and let Γ 0 1 ( S 3 ) denote the space of nonsingular vector fields on S 3 with the C 1 topology. Under what conditions are two elements from Γ 0 1 ( S 3 ) homotopic ? There are several examples of nonsingular vector fields on S 3 . However, they are all homotopic to the tangent fields of the fibrations of S 3 due to H. Hopf (there are two such classes).We construct some new examples of vector fields which can be classified geometrically. Each of these examples...

Some generalized Coxeter groups and their orbifolds.

Marcel Hagelberg, Rubén A. Hidalgo (1997)

Revista Matemática Iberoamericana

In this note we construct examples of geometric 3-orbifolds with (orbifold) fundamental group isomorphic to a (Z-extension of a) generalized Coxeter group. Some of these orbifolds have either euclidean, spherical or hyperbolic structure. As an application, we obtain an alternative proof of theorem 1 of Hagelberg, Maclaughlan and Rosenberg in [5]. We also obtain a similar result for generalized Coxeter groups.

Some lagrangian invariants of symplectic manifolds

Michel Nguiffo Boyom (2007)

Banach Center Publications

The KV-homology theory is a new framework which yields interesting properties of lagrangian foliations. This short note is devoted to relationships between the KV-homology and the KV-cohomology of a lagrangian foliation. Let us denote by F (resp. V F ) the KV-algebra (resp. the space of basic functions) of a lagrangian foliation F. We show that there exists a pairing of cohomology and homology to V F . That is to say, there is a bilinear map H q ( F , V F ) × H q ( F , V F ) V F , which is invariant under F-preserving symplectic diffeomorphisms....

Some natural operations between connections on fibred manifolds

Doupovec, Miroslav, Vondra, Alexandr (1996)

Proceedings of the Winter School "Geometry and Physics"

Given a fibered manifold Y X , a 2-connection on Y means a section J 1 Y J 2 Y . The authors determine all first order natural operators transforming a 2-connection on Y and a classical linear connection on X into a connection on J 1 Y Y . (The proof implies that there is no first order natural operator transforming 2-connections on Y into connections on J 1 Y Y .) Using this result, the authors deduce several properties of characterizable connections on J 1 Y X .

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