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Let M denote a compact, orientable, 3-dimensional manifold and let a denote a contact 1-form on M; thus the wedge product of a with da is nowhere zero. This article explains how the Seiberg-Witten Floer homology groups as defined for any…

Symplectic Geometry · Mathematics 2007-05-23 Clifford Henry Taubes

We prove that if an orientable 3-manifold $M$ admits a complete Riemannian metric whose scalar curvature is positive and has a subquadratic decay at infinity, then it decomposes as a (possibly infinite) connected sum of spherical manifolds…

Differential Geometry · Mathematics 2025-05-13 Florent Balacheff , Teo Gil Moreno de Mora Sardà , Stéphane Sabourau

For a smooth compact Riemannian manifold with positive Yamabe invariant, positive Q curvature and dimension at least 5, we prove the existence of a conformal metric with constant Q curvature. Our approach is based on the study of extremal…

Differential Geometry · Mathematics 2015-10-07 Fengbo Hang , Paul C. Yang

We study normal CR compact manifolds in dimension 3. For a choice of a CR Reeb vector field, we associate a Sasakian metric on them, and we classify those metrics. As a consequence, the underlying manifolds are topologically finite quotiens…

Differential Geometry · Mathematics 2007-05-23 F. A. Belgun

In this article, the author defines an invariant of rational homology 3-spheres equipped with a contact structure as an element of a cohomotopy set of the Seiberg-Witten Floer spectrum as defined in Manolescu (2003). Furthermore, in light…

Symplectic Geometry · Mathematics 2023-07-06 Bruno Roso

A non-degenerate contact form is lacunary if the indexes of every contractible periodic Reeb orbit have the same parity. To the best of our knowledge, every contact form with finitely many periodic orbits known so far is non-degenerate and…

Symplectic Geometry · Mathematics 2026-02-26 Miguel Abreu , Leonardo Macarini

We consider quantum invariants of 3-manifolds associated with arbitrary simple Lie algebras. Using the symmetry principle we show how to decompose the quantum invariant as the product of two invariants, one of them is the invariant…

Quantum Algebra · Mathematics 2007-05-23 Thang T. Q. Le

We determine the local equivalence class of the Seiberg-Witten Floer stable homotopy type of a spin rational homology 3-sphere $Y$ embedded into a spin rational homology $S^{1} \times S^{3}$ with a positive scalar curvature metric so that…

Differential Geometry · Mathematics 2021-05-26 Hokuto Konno , Masaki Taniguchi

Given an orientation-preserving and area-preserving homeomorphism $f$ of the sphere, we prove that every point which is in the common boundary of three pairwise disjoint invariant open topological disks must be a fixed point. As an…

Dynamical Systems · Mathematics 2018-06-05 Andres Koropecki , Patrice Le Calvez , Fabio Armando Tal

Assume that $M$ is a CR compact manifold without boundary and CR Yamabe invariant $\mathcal{Y}(M)$ is positive. Here, we devote to study a class of sharp Hardy-Littlewood-Sobolev inequality as follows \begin{equation*} \Bigl| \int_M\int_M…

Analysis of PDEs · Mathematics 2021-06-15 Yazhou Han

A long-standing conjecture in complex geometry says that a compact Hermitian manifold with constant holomorphic sectional curvature must be K\"ahler when the constant is non-zero and must be Chern flat when the constant is zero. The…

Differential Geometry · Mathematics 2023-02-24 Peipei Rao , Fangyang Zheng

In this expository paper we discuss several properties on closed aspherical parabolic ${\sfG}$-manifolds $X/\Gamma$. These are manifolds $X/\Gamma$, where $X$ is a smooth contractible manifold with a parabolic ${\sfG}$-structure for which…

Differential Geometry · Mathematics 2023-09-26 Oliver Baues , Yoshinobu Kamishima

We construct an enhanced version of knot contact homology, and show that we can deduce from it the group ring of the knot group together with the peripheral subgroup. In particular, it completely determines a knot up to smooth isotopy. The…

Symplectic Geometry · Mathematics 2021-02-02 Tobias Ekholm , Lenhard Ng , Vivek Shende

We examine the class of compact Hermitian manifolds with constant holomorphic sectional curvature. Such manifolds are conjectured to be K\"ahler (hence a complex space form) when the constant is non-zero and Chern flat (hence a quotient of…

Differential Geometry · Mathematics 2022-10-18 Wu Zhou , Fangyang Zheng

Following previous work, we continue the study of infinitesimal methods in mixed Hodge theory. In the first part, inspired by the deformation theory of curves on Calabi-Yau threefolds, we study deformations of smooth $\mathbb{Q}$-log…

Algebraic Geometry · Mathematics 2026-01-21 Rodolfo Aguilar

We prove a compactness theorem for holomorphic curves in 4-dimensional symplectizations that have embedded projections to the underlying 3-manifold. It strengthens the cylindrical case of the SFT compactness theorem by using intersection…

Symplectic Geometry · Mathematics 2008-03-07 Chris Wendl

In [LMO] a 3-manifold invariant $\Omega(M)$ is constructed using a modification of the Kontsevich integral and the Kirby calculus. The invariant $\Omega$ takes values in a graded Hopf algebra of Feynman 3-valent graphs. Here we show that…

q-alg · Mathematics 2008-02-03 Thang T. Q. Le

We construct a new infinite-dimensional family of homogeneous quasimorphisms on the group of Hamiltonian diffeomorphisms of the two-sphere. Moreover, for any constant $K$ less than the total area of the sphere, we produce unbounded…

Symplectic Geometry · Mathematics 2025-12-01 Yongsheng Jia , Richard Webb

We show that a closed almost K\"ahler 4-manifold of globally constant holomorphic sectional curvature $k\geq 0$ with respect to the canonical Hermitian connection is automatically K\"ahler. The same result holds for $k<0$ if we require in…

Differential Geometry · Mathematics 2017-09-18 Mehdi Lejmi , Markus Upmeier

We show that in the first sub-Riemannian Heisenberg group there are intrinsic graphs of smooth functions that are both critical and stable points of the sub-Riemannian perimeter under compactly supported variations of contact…

Differential Geometry · Mathematics 2017-08-24 Sebastiano Golo