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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

This article is concerned with Chern class and Chern number inequalities on polarized manifolds and nef vector bundles. For a polarized pair $(M,L)$ with $L$ very ample, our first main result is a family of sharp Chern class inequalities.…

Differential Geometry · Mathematics 2022-05-11 Ping Li , Fangyang Zheng

In this note, we prove a 2-systolic inequality on compact positive scalar curvature K\"ahler surfaces admitting a nonconstant holomorphic map to a positive-genus compact Riemann surface. According to the classification of positive scalar…

Differential Geometry · Mathematics 2026-03-12 Zehao Sha

In this note, we prove that for a complete noncompact three dimensional Riemannian manifold with bounded sectional curvature, if it has uniformly positive scalar curvature, then there is a uniform lower bound on the injectivity radius.

Differential Geometry · Mathematics 2023-02-24 Conghan Dong

In this note we provide a proof of the following: Any compact KRS with positive bisectional curvature is biholomorphic to the complex projective space. As a corollary, we obtain an alternative proof of the Frankel conjecture by using the…

Differential Geometry · Mathematics 2009-06-21 Xiuxiong Chen , Song Sun , Gang Tian

We show that for any solution to the K\"ahler-Ricci flow with positive bisectional curvature on a compact K\"ahler manifold $M^n$, the bisectional curvature has a uniform positive lower bound. As a consequence, the solution converges…

Differential Geometry · Mathematics 2010-03-29 Huai-Dong Cao , Meng Zhu

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

Differential Geometry · Mathematics 2022-07-18 Yulu Li , Fangyang Zheng

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 obtain a class of Kaehler Einstein structures on the nonzero cotangent bundle of a Riemannian manifold of positive constant sectional curvature. The obtained class of Kaehler Einstein structure depends on one essential parameter, cannot…

Differential Geometry · Mathematics 2007-05-23 Dumitru Daniel Porosniuc

We initiate the study of an analogue of the Yamabe problem for complex manifolds. More precisely, fixed a conformal Hermitian structure on a compact complex manifold, we are concerned in the existence of metrics with constant Chern scalar…

Differential Geometry · Mathematics 2017-09-05 Daniele Angella , Simone Calamai , Cristiano Spotti

Kodaira embedding theorem provides an effective characterization of projectivity of a K\"ahler manifold in terms the second cohomology. Recently X. Yang [21] proved that any compact K\"ahler manifold with positive holomorphic sectional…

Differential Geometry · Mathematics 2023-02-24 Lei Ni , Fangyang Zheng

We prove that all currently known examples of manifolds with nonnegative sectional curvature satisfy a stronger condition: their curvature operator can be modified with a 4-form to become positive-semidefinite.

Differential Geometry · Mathematics 2017-08-31 Renato G. Bettiol , Ricardo A. E. Mendes

We show that if $(M,\omega)$ is any compact K\"ahler manifold, then the blowup of $M$ at any point furnishes a K\"ahler metric with scalar curvature globally and arbitrarily $C^0$-close to the scalar curvature of $\omega$. It follows that…

Differential Geometry · Mathematics 2026-01-28 Garrett M. Brown

In this paper, we establish a "pseudo-effective" version of the holonomy principle for compact K\"{a}hler manifolds with nonnegative holomorphic sectional curvature. As applications, we prove that if a compact complex manifold $M$ admits a…

Differential Geometry · Mathematics 2024-08-07 Shiyu Zhang , Xi Zhang

In this paper, we prove some rigidity theorems for compact Bach-flat $n$-manifold with the positive constant scalar curvature. In particular, our conditions in Theorem 1.4 have the additional properties of being sharp.

Differential Geometry · Mathematics 2017-07-25 Haiping Fu , Jianke Peng

In this paper we prove that, under natural assumptions, the scalar curvature of a Kaehler-Einstein metric on a compactification of C^n is strictly positive.

Differential Geometry · Mathematics 2013-07-11 Claudio Arezzo , Andrea Loi

We classify compact almost-K\"ahler four manifolds with nonnegative biorthogonal curvature.

Differential Geometry · Mathematics 2023-11-29 Inyoung Kim

In this paper, we study MRC fibrations of compact K\"ahler manifolds with partially semi-positive curvature. We first prove that a compact K\"ahler manifold is rationally connected if its tangent bundle is BC-$p$ positive for all $1\leq…

Differential Geometry · Mathematics 2026-03-09 Shiyu Zhang , Xi Zhang

In this paper we obtain three results concerning the geometry of complete noncompact positively curved K\"{a}hler manifolds at infinity. The first one states that the order of volume growth of a complete noncompact K\"{a}hler manifold with…

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

We investigate four-dimensional gradient shrinking Ricci solitons with positive modified sectional curvature. Our first main result shows that if the norm of the self-dual Weyl tensor and the scalar curvature satisfy a certain sharp…

Differential Geometry · Mathematics 2025-09-29 Xiaodong Cao , Ernani Ribeiro , Hosea Wondo