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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 article we study compact K\ahler manifolds satisfying a certain nonnegativity condition on the bisectional curvature. Under this condition, we show that the scalar curvature is nonnegative and that the first Chern class is positive…

Differential Geometry · Mathematics 2011-09-01 Albert Chau , Luen-Fai Tam

In this article we study the concept of quaternionic bisectional curvature introduced by B. Chow and D. Yang for quaternion-K\"ahler manifolds. We show that non-negative quaternionic bisectional curvature is only realized for the…

Differential Geometry · Mathematics 2024-10-18 Oscar Macia , Uwe Semmelmann , Gregor Weingart

In this paper we give a partial affirmative answer to a conjecture of Greene-Wu and Yau. We prove that a complete noncompact K\"ahler surface with positive and bounded sectional curvature and with finite analytic Chern number $c_{1}(M)^{2}$…

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

In this article we continue the study of the two curvature notions for K\"ahler manifolds introduced by the first named author earlier: the so-called cross quadratic bisectional curvature (CQB) and its dual ($^d$CQB). We first show that…

Differential Geometry · Mathematics 2025-03-18 Lei Ni , Fangyang Zheng

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 any complete non-compact K\"ahler surface with positive sectional curvature is biholomorphic to $\mathbb{C}^2$, establishing the two dimensional case of the weaker form of Yau's uniformisation conjecture. In contrast to all…

Differential Geometry · Mathematics 2026-04-14 Ved Datar , Vamsi Pritham Pingali , Harish Seshadri

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

In this paper, we study any K\"ahler manifold where the positive orthogonal bisectional curvature is preserved on the K\"ahler Ricci flow. Naturally, we always assume that the first Chern class $C_1$ is positive. In particular, we prove…

Differential Geometry · Mathematics 2007-05-23 X. X. Chen

We give a mathematical exposition of the Page metric, and introduce an efficient coordinate system for it. We carefully examine the submanifolds of the underlying smooth manifold, and show that the Page metric does not have positive…

Differential Geometry · Mathematics 2019-04-11 Mustafa Kalafat , Caner Koca

Motivated by the recent work of Wu and Yau on the ampleness of canonical line bundle for compact K\"ahler manifolds with negative holomorphic sectional curvature, we introduce a new curvature notion called $\textbf{real bisectional…

Differential Geometry · Mathematics 2023-03-31 Xiaokui Yang , Fangyang Zheng

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

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 study the asymptotic behavior of the K\"ahler-Ricci flow on K\"ahler manifolds of nonnegative holomorphic bisectional curvature. Using these results we prove that a complete noncompact K\"ahler manifold with nonnegative bounded…

Differential Geometry · Mathematics 2016-09-07 Albert Chau , Luen-Fai Tam

Given compact Lie groups H\subset G, we study the space of G-invariant metrics on G/H with nonnegative sectional curvature. For an intermediate subgroup K between H and G, we derive conditions under which enlarging the Lie algebra of K…

Differential Geometry · Mathematics 2008-06-24 Lorenz Schwachhofer , Kristopher Tapp

For a compact relative K\"ahler fibration over a compact K\"ahler manifold with negative holomorphic sectional curvature, if the relative K\"ahler form on each fiber also exhibits negative holomorphic sectional curvature, we can construct…

Differential Geometry · Mathematics 2026-01-16 Xueyuan Wan

We show that a compact complex surface which admits a conformally K\"ahler metric g of positive orthogonal holomorphic bisectional curvature is biholomorphic to the complex projective plane. In addition, if g is a Hermitian metric which is…

Differential Geometry · Mathematics 2015-04-07 Mustafa Kalafat , Caner Koca

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

One of the main purposes of this paper is to prove that on a complete K\"ahler manifold of dimension $m$, if the holomorphic bisectional curvature is bounded from below by -1 and the minimum spectrum $\lambda_1(M) \ge m^2$, then it must…

Differential Geometry · Mathematics 2007-05-23 Peter Li , Jiaping Wang

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
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