English
Related papers

Related papers: Almost-K\"ahler four manifolds with nonnegative bi…

200 papers

In this note we classify compact 4-manifolds with harmonic Weyl tensor and nonnegative biorthogonal curvature

Differential Geometry · Mathematics 2015-05-21 Ezio Araujo Costa

A classification theorem for nearly K\"ahler manifolds of constant antiholomorphic sectional curvature is proved.

Differential Geometry · Mathematics 2010-09-15 Georgi Ganchev , Ognian Kassabov

We show that a compact almost-K\"ahler four manifold $(M, g, \omega)$ with harmonic self-dual Weyl curvature and constant scalar curvature is K\"ahler if $c_{1}\cdot\omega\geq 0$. We also prove an integral curvature inequality for compact…

Differential Geometry · Mathematics 2023-11-29 Inyoung Kim

The aim of this paper is to classify compact Kahler manifolds with quasi-constant holomorphic sectional curvature.

Differential Geometry · Mathematics 2016-02-26 Wlodzimierz Jelonek

We give four constructions of non-$\partial\bar\partial$ (hence non-K\"ahler) manifolds: (1) A simply connected page-$1$-$\partial\bar\partial$-manifold (2) A simply connected $dd^c+3$-manifold (3) For any $r\geq 2$, a simply connected…

Algebraic Geometry · Mathematics 2023-06-27 Hisashi Kasuya , Jonas Stelzig

It is proved that if an almost K\"ahler manifold of dimension greater or equal to 8 is of pointwise constant antiholomorphic sectional curvature, then it is a complex space form.

Differential Geometry · Mathematics 2010-10-08 Maria Falcitelli , Angela Farinola , Ognian Kassabov

We show that a compact quaternionic-K\"ahler manifold with positive scalar curvature and nonnegative sectional curvature is isometric to a symmetric space. This extends a classical theorem of Berger.

Differential Geometry · Mathematics 2025-06-30 S. Brendle , U. Semmelmann

We classify, up to homeomorphisms, the closed simply-connected 4-manifolds that admit a Riemannian metric for which averages of pairs of sectional curvatures of orthogonal planes are positive.

Differential Geometry · Mathematics 2017-12-29 Renato G. Bettiol

We classify non-algebraic compact K\"ahler threefolds admitting an endomorphism $f: X \to X$ of degree at least two.

Algebraic Geometry · Mathematics 2017-11-10 Andreas Höring , Thomas Peternell

This paper proves that the universal covering of a compact K\"{a}hler manifold with small positive sectional curvature in a certain sense is contractible.

Differential Geometry · Mathematics 2025-02-20 Yuguang Zhang

In this work, we investigate compact K\"ahler manifolds with non-negative or quasi-positive mixed curvature coming from a linear combination of the Ricci and holomorphic sectional curvature, which covers various notions of curvature…

Differential Geometry · Mathematics 2024-08-27 Jianchun Chu , Man-Chun Lee , Jintian Zhu

We construct a compact K\"ahler manifold of nonnegative quadratic bisectional curvature, which does not admit any K\"ahler metric of nonnegative orthogonal bisectional curvature. The manifold is a 7-dimensional K\"ahler C-space with second…

Differential Geometry · Mathematics 2011-10-11 Qun Li , Damin Wu , Fangyang Zheng

Let (M,g) be a simply connected complete Kahler manifold with nonpositive sectional curvature. Assume that g has constant negative holomorphic sectional curvature outside a compact set. We prove that M is then biholomorphic to the unit ball…

Functional Analysis · Mathematics 2007-05-23 Harish Seshadri , Kaushal Verma

We show that every closed symplectic four-dimensional manifold admits compatible almost Kaehler metrics of negative scalar curvature.

Differential Geometry · Mathematics 2007-05-23 Jongsu Kim

We classify compact self-dual almost-K\"ahler four manifolds of positive type and zero type. In particular, using LeBrun's result, we show that any self-dual almost-K\"ahler metric on a manifold which is diffeomorphic to $\mathbb{CP}_{2}$…

Differential Geometry · Mathematics 2023-11-30 Inyoung Kim

It is proved that if an AK2-manifold of dimension greater or equal to 6 is of pointwise constant antiholomorphic sectional curvature, then it is a 6-dimensional manifold of constant negative sectional curvature or a K\"ahler manifold of…

Differential Geometry · Mathematics 2010-09-15 Ognian Kassabov

The class of the Riemannian almost product manifolds with nonintegrable structure is considered. Some identities for curvature tensor as certain invariant tensors and quantities are obtained.

Differential Geometry · Mathematics 2009-07-14 Dimitar Mekerov

In this note we prove that a four-dimensional compact oriented half-confor\-mally flat Riemannian manifold $M^4$ is topologically $\mathbb{S}^{4}$ or $\mathbb{C}\mathbb{P}^{2},$ provided that the sectional curvatures all lie in the interval…

Differential Geometry · Mathematics 2020-03-17 R. Diógenes , E. Ribeiro , E. Rufino

We consider 6-dimensional strict nearly Kaehler manifolds acted on by a compact, cohomogeneity one automorphism group G. We classify the compact manifolds of this class up to G-diffeomorphisms. We also prove that the manifold has constant…

Differential Geometry · Mathematics 2015-05-13 Fabio Podesta' , Andrea Spiro

We prove that compact quaternionic-K\"ahler manifolds of positive scalar curvature admit no almost complex structure, even in the weak sense, except for the complex Grassmannians $Gr_2(C^{n+2})$. We also prove that irreducible inner…

Differential Geometry · Mathematics 2011-04-26 Paul Gauduchon , Andrei Moroianu , Uwe Semmelmann
‹ Prev 1 2 3 10 Next ›