English
Related papers

Related papers: Almost Non-positive K\"{a}hler Manifolds

200 papers

Let $X$ be a compact K\"ahler manifold. We prove that if $X$ admits a smooth Hermitian metric $\omega$ with quasi-positive second Chern-Ricci curvature $\mathrm{Ric}^{(2)}(\omega)$, then $X$ is projective and rationally connected. In…

Differential Geometry · Mathematics 2020-06-25 Xiaokui Yang

Given any integer $n\geq 2$, we construct a compact K\"ahler-Einstein manifold of dimension n of negative sectional curvature which is not covered by the ball.

Differential Geometry · Mathematics 2026-05-05 Henri Guenancia , Ursula Hamenstädt

Motivated by a previous work of Zheng and the second named author, we study pinching constants of compact K\"ahler manifolds with positive holomorphic sectional curvature. In particular we prove a gap theorem following the work of Petersen…

Differential Geometry · Mathematics 2017-09-11 Xiaodong Cao , Bo Yang

We prove that every compact K\"ahler threefold has arbitrarily small deformations to some projective manifolds, thereby solving the Kodaira problem in dimension 3.

Algebraic Geometry · Mathematics 2024-01-31 Hsueh-Yung Lin

In the paper we prove a factorization theorem for representations of fundamental groups of compact K\"{a}hler manifolds ({\em K\"{a}hler groups}) into solvable matrix groups. We apply this result to prove that the universal covering of a…

Complex Variables · Mathematics 2007-05-23 Alexander Brudnyi

We classify these threefolds, which are the ones such that their universal cover is not compact and not covered by positive-dimensional compact analytic subsets. We show that these threefolds have nonnegative Kodaira dimension, and that…

Algebraic Geometry · Mathematics 2007-05-23 F. Campana , Q. Zhang

A Hopf manifold is a compact complex manifold of which the universal covering is C^n\{0}. In this note we show that any Hopf manifold admits a locally conformally Kaehler structure (shortly lcK structure), by constructing a complex analytic…

Differential Geometry · Mathematics 2023-06-16 Keizo Hasegawa

In this work we consider compact K\"ahler manifolds with non-positive mixed curvature which is a "convex combination" of Ricci curvature and holomorphic sectional curvature. We show that in this case, the canonical line bundle is nef.…

Differential Geometry · Mathematics 2022-05-03 Jianchun Chu , Man-Chun Lee , Luen-Fai Tam

A product of K\"ahler manifolds also carries a K\"ahler metric. In this short note we would like to study the product of generalized $p-$K\"ahler manifolds, compact or not. The results we get extend the known results (balanced, SKT, sG…

Differential Geometry · Mathematics 2017-02-16 Lucia Alessandrini

In this paper, by combining techniques from Ricci flow and algebraic geometry, we prove the following generalization of the classical uniformization theorem of Riemann surfaces. Given a complete noncompact complex two dimensional K\"ahler…

Differential Geometry · Mathematics 2007-05-23 Bing-Long Chen , Siu-Hung Tang , Xi-Ping Zhu

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

In a recent work, Kai Tang conjectured that any compact Hermitian manifold with non-zero constant mixed curvature must be K\"ahler. He confirmed the conjecture in complex dimension $2$ and for Chern K\"ahler-like manifolds in general…

Differential Geometry · Mathematics 2025-10-14 Shuwen Chen , Fangyang Zheng

We prove that compact complex manifolds with admitting metrics with negative Chern curvature operator either admit a $dd^c$-exact positive (1,1) current, or are K\"ahler with ample canonical bundle. In the case of complex surfaces we obtain…

Differential Geometry · Mathematics 2019-04-01 Man-Chun Lee , Jeffrey Streets

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

We prove that a complete noncompact K\"{a}hler manifold $M^{n}$of positive bisectional curvature satisfying suitable growth conditions is biholomorphic to a pseudoconvex domain of {\bf C}$^{n}$ and we show that the manifold is topologically…

Differential Geometry · Mathematics 2007-05-23 Bing-Long Chen , Xi-Ping Zhu

We study an odd-dimensional analogue of the Goldberg conjecture for compact Einstein almost K\"ahler manifolds. We give an explicit non-compact example of an Einstein almost cok\"ahler manifold that is not cok\"ahler. We prove that compact…

Differential Geometry · Mathematics 2016-01-11 Diego Conti , Marisa Fernández

It is a basic tenet in complex geometry that {\it negative} curvature corresponds, in a suitable sense, to the absence of rational curves on, say, a complex projective manifold, while {\it positive} curvature corresponds to the abundance of…

Algebraic Geometry · Mathematics 2012-06-13 Gordon Heier , Bun Wong

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 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

In this short note, using Siu-Yau's method [14], we give a new proof that any n-dimensional compact Kahler manifold with positive orthogonal bisectional curvature must be biholomorphic to $\mathbb{P}^n$.

Differential Geometry · Mathematics 2017-10-30 Huitao Feng , Kefeng Liu , Xueyuan Wan