Soit V une variété close de dimension 3. Dans cet article, on montre que les classes dhomotopie de champs de plans sur V qui contiennent des structures de contact tendues sont en nombre fini et que, si V est atoroïdale, les classes disotopie des structures de contact tendues sur V sont elles aussi en nombre fini.
In this paper we study topological properties of stable Hamiltonian structures. In particular, we prove the following results in dimension three: The space of stable Hamiltonian structures modulo homotopy is discrete; stable Hamiltonian structures are generically Morse-Bott (i.e. all closed orbits are Bott nondegenerate) but not Morse; the standard contact structure on is homotopic to a stable Hamiltonian structure which cannot be embedded in . Moreover, we derive a structure theorem for stable...
We review topological properties of Kähler and symplectic manifolds, and of their odd-dimensional counterparts, coKähler and cosymplectic manifolds. We focus on formality, Lefschetz property and parity of Betti numbers, also distinguishing the simply-connected case (in the Kähler/symplectic situation) and the b1 = 1 case (in the coKähler/cosymplectic situation).
2000 Mathematics Subject Classification: 37J55, 53D10, 53D17, 53D35.In this paper, we study contact forms on a 3-manifold having a common Reeb vector field R. The main result is that when the contact forms induce the same orientation, they are diffeomorphic.