English
Related papers

Related papers: Sasaki structures distinguished by their basic Hod…

200 papers

We make some elementary observations concerning subcritically Stein fillable contact structures on 5-manifolds. Specifically, we determine the diffeomorphism type of such contact manifolds in the case the fundamental group is finite cyclic,…

Geometric Topology · Mathematics 2019-08-15 Fan Ding , Hansjörg Geiges , Guangjian Zhang

Let $(\Sigma ,\xi ',\omega)$ be a close almost contact $(2n-1)$-manifold. Then, by McDuff's theorem, we prove that $\xi '$ is homotopic to a contact structure $\xi $. This answers a question proposed by Chern.

General Mathematics · Mathematics 2013-11-01 Renyi Ma

We introduce a variant of contact homology for convex open contact manifolds. As an application, we prove the existence of (in fact, infinitely many) exotic tight contact structures on $\mathbb{R}^{2n-1}$ for all $n>2$.

Symplectic Geometry · Mathematics 2025-06-12 François-Simon Fauteux-Chapleau , Joseph Helfer

Using recent work on high dimensional Lutz twists and families of Weinstein structures we show that any almost contact structure on a 5-manifold is homotopic to a contact structure.

Symplectic Geometry · Mathematics 2013-02-05 John B. Etnyre

A geometric obstruction, the so called "plastikstufe", for a contact structure to not being fillable has been found by K. Niederkruger. This generalizes somehow the concept of overtwisted structure to dimensions higher than 3. This paper…

Symplectic Geometry · Mathematics 2014-11-11 Francisco Presas

In this article we study a class of normal{\theta}complex{\theta}contact{\theta}metric{\theta}manifold which is called a complex Sasakian manifold. This kind of manifold has a globally defined complex contact form and normal complex contact…

Differential Geometry · Mathematics 2021-01-05 Aysel Turgut Vanli , İnan Ünal , Keziban Avcu

Contact path geometries are curved geometric structures on a contact manifold comprising smooth families of paths modeled on the family of all isotropic lines in the projectivization of a symplectic vector space. Locally such a structure is…

Differential Geometry · Mathematics 2007-05-23 Daniel J. F. Fox

We describe a necessary and sufficient condition for a principal circle bundle over an even-dimensional manifold to carry an invariant contact structure. As a corollary it is shown that all circle bundles over a given base manifold carry an…

Symplectic Geometry · Mathematics 2014-02-26 Fan Ding , Hansjörg Geiges

In this paper we study compact Sasaki manifolds in view of transverse K\"ahler geometry and extend some results in K\"ahler geometry to Sasaki manifolds. In particular we define integral invariants which obstruct the existence of transverse…

Differential Geometry · Mathematics 2007-05-23 Akito Futaki , Hajime Ono , Guofang Wang

We generalize to nearly K\"ahler manifolds of arbitrary dimensions most of the Hodge-theoretic results for nearly K\"ahler $6$-manifolds that were established by Verbitsky. In particular, for a compact nearly K\"ahler manifold of any…

Differential Geometry · Mathematics 2026-04-07 Michael Albanese , Spiro Karigiannis , Lucía Martín-Merchán , Aleksandar Milivojević

We give necessary and sufficient conditions for a closed orientable 9-manifold M to admit an almost contact structure. The conditions are stated in terms of the Stiefel-Whitney classes of M and other more subtle homotopy invariants of M. By…

Symplectic Geometry · Mathematics 2020-11-20 Diarmuid Crowley , Huijun Yang

Recent renewed interest in Sasakian manifolds is due mainly to the fact that they can provide examples of generalized Einstein manifolds, manifolds which are of great interest in mathematical models of various aspects of physical phenomena.…

Differential Geometry · Mathematics 2016-05-16 Robert Wolak

We show that the Malcev Lie algebra of the fundamental group of a compact $2n+1$-dimensional Sasakian manifold with $n\ge 2$ admits a quadratic presentation by using Morgan's bigradings of minimal models of mixed-Hodge diagrams. By using…

Geometric Topology · Mathematics 2015-11-13 Hisashi Kasuya

It is introduced a differentiable manifold with almost contact 3-structure which consists of an almost contact metric structure and two almost contact B-metric structures. The product of this manifold and a real line is an almost…

Differential Geometry · Mathematics 2017-11-21 Mancho Manev

In this paper we investigate the Kodaira dimension of almost complex $4$-manifolds with torsion first Chern class. First, we prove that, if the almost complex structure is also tamed, the only possible values for the Kodaira dimension are…

Differential Geometry · Mathematics 2025-11-26 Lorenzo Sillari , Adriano Tomassini

We interpret the property of having an infinitesimal symmetry as a variational property in certain geometric structures. This is achieved by establishing a one-to-one correspondence between a class of cone structures with an infinitesimal…

Differential Geometry · Mathematics 2026-04-03 Omid Makhmali , Katja Sagerschnig

I begin by giving a general discussion of completely integrable Hamiltonian systems in the setting of contact geometry. We then pass to the particular case of toric contact structures on the manifold $S^2\times S^3$. In particular we give a…

Symplectic Geometry · Mathematics 2011-06-16 Charles P. Boyer

We show that for all $n \ge 3$, any $(2n+1)$-dimensional manifold that admits a tight contact structure, also admits a tight but non-fillable contact structure, in the same almost contact class. For $n=2$, we obtain the same result,…

Symplectic Geometry · Mathematics 2026-03-17 Jonathan Bowden , Fabio Gironella , Agustin Moreno , Zhengyi Zhou

In this paper, we show that a generalized Sasakian space form of dimension greater than three is either of constant sectional curvature; or a canal hypersurface in Euclidean or Minkowski spaces; or locally a certain type of twisted product…

Differential Geometry · Mathematics 2015-08-04 Avik De , Tee-How Loo

In this note, we describe the geometry of the quaternionic Heisenberg groups from a Riemannian viewpoint. We show, in all dimensions, that they carry an almost $3$-contact metric structure which allows us to define the metric connection…

Differential Geometry · Mathematics 2015-10-28 Ilka Agricola , Ana Cristina Ferreira , Reinier Storm