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Related papers: On quaternionic bisectional curvature

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This note proves orbifold versions of Kobayashi's theorem. The main result asserts that a compact K\"ahler orbifold with non-negative Ricci curvature, along with certain conditions regarding singularities, is simply connected.

Differential Geometry · Mathematics 2026-04-09 Yuguang Zhang

As was recently observed by M. Xu and J. Wolf, there is a gap in Berard Bergery's classification of odd dimensional positively curved homogeneous spaces. Since this classification has been used in other papers as well, we give a modern,…

Differential Geometry · Mathematics 2015-03-24 Burkhard Wilking , Wolfgang Ziller

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 introduce the weighted orthogonal Ricci curvature -- a two-parameter version of Ni--Zheng's orthogonal Ricci curvature. This curvature serves as a very natural object in the study of the relationship between the Ricci curvature(s) and…

Differential Geometry · Mathematics 2021-11-02 Kyle Broder , Kai Tang

In this note, we give a brief survey on some recent developments of biharmonic submanifolds. After reviewing some recent progress on Chen's biharmonic conjecture, the Generalized Chen's conjecture on biharmonic submanifolds of…

Differential Geometry · Mathematics 2015-12-01 Ye-Lin Ou

In this paper, we establish a structure theorem for a smooth projective variety $X$ with semi-positive holomorphic sectional curvature. Our structure theorem contains the solution for Yau's conjecture and it can be regarded as a natural…

Differential Geometry · Mathematics 2018-11-13 Shin-ichi Matsumura

We study the class of non-degenerate homogeneous structures of linear type in the pseudo-K\"ahler, para-K\"ahler, pseudo-quaternion K\"ahler and para-quaternion K\"ahler cases. We show that these structures characterize spaces of constant…

Differential Geometry · Mathematics 2013-11-14 Ignacio Luján , Andrew Swann

For a compact K\"{a}hler-Einstein manifold $M$ of dimension $n\ge 2$, we explicitly write the expression $-c_1^n(M)+\frac{2(n+1)}{n}c_2(M)c_1^{n-2}(M)$ in the form of certain integral on the holomorphic sectional curvature and its average…

Differential Geometry · Mathematics 2025-03-25 Rong Du

We show that for all very special quaternionic manifolds a different N=1 reduction exists, defining a Kaehler Geometry which is ``dual'' to the original very special Kaehler geometry with metric G_{a\bar{b}}= - \partial_a \partial_b \ln V…

High Energy Physics - Theory · Physics 2009-11-10 R. D'Auria , Sergio Ferrara , M. Trigiante

The Kaehler manifolds of quasi-constant holomorphic sectional curvatures are introduced as Kaehler manifolds with complex distribution of codimension two, whose holomorphic sectional curvature only depends on the corresponding point and the…

Differential Geometry · Mathematics 2008-03-04 Georgi Ganchev , Vesselka Mihova

In this paper, we study global properties of continuous plurisubharmonic functions on complete noncompact K\"ahler manifolds with nonnegative bisectional curvature and their applications to the structure of such manifolds. We prove that…

Differential Geometry · Mathematics 2007-05-23 Lei Ni , Luen-Fai Tam

We study rigidity on certain K\"ahler manifolds with nonnegative Ricci curvature. Among others things, we show that a complete noncompact K\"ahler surface with nonnegative Ricci curvature, Euclidean volume growth and quadratic curvature…

Differential Geometry · Mathematics 2025-10-14 Gang Liu

An old problem asks whether a Riemannian manifold can be isospectral to a Riemannian orbifold with nontrivial singular set. In this short note we show that under the assumption of Schanuel's conjecture in transcendental number theory, this…

Differential Geometry · Mathematics 2015-04-09 Benjamin Linowitz , Jeffrey S. Meyer

In this paper, we prove that any K\"ahler Ricci shrinker surface has bounded sectional curvature. Combining this estimate with earlier work by many authors, we provide a complete classification of all K\"ahler Ricci shrinker surfaces.

Differential Geometry · Mathematics 2025-02-18 Yu Li , Bing Wang

We show that the CR structure on the twistor space of a quaternionic contact structure described by Biquard is normal if and only if the Ricci curvature of the Biquard connection commutes with the endomorphisms in the quaternionic structure…

Differential Geometry · Mathematics 2011-07-07 Johann Davidov , Stefan Ivanov , Ivan Minchev

The paper is devoted to the investigation of four-dimensional Kahler manifolds admitting non-affine H-projective mappings. We find all such manifolds which are non-Einstein. In the paper also Kahler manifolds admitting infinitesimal…

dg-ga · Mathematics 2008-02-03 Dmitry A. Kalinin

We introduce a compact moduli of noncommutative quadrics, and show that it is the weighted projective space of weight (2,4,4,6). We also introduce a compact moduli of potentials for the conifold quiver, and show that it is the weighted…

Algebraic Geometry · Mathematics 2014-03-05 Shinnosuke Okawa , Kazushi Ueda

In this paper we review the development and recent results of the Siu-Yang conjecture which is that every K\"ahler-Einstein compact complex manifold of complex dimension two with negative sectional curvature is biholomorphic to a compact…

Differential Geometry · Mathematics 2021-10-01 X. Zhao

In this article, we study and analyze the \phi-sectional curvature induced by a statistical structure on an almost contact metric manifold. We demonstrate that this sectional curvature is always non-positive. Additionally, we present…

Differential Geometry · Mathematics 2025-07-02 Abbas Heydari , Sadegh Mohammadi

We introduce the notion of tame $\rho$-quaternionic manifold that permits the construction of a finite family of $\rho$-connections, significant for the geometry involved. This provides, for example, the following: (1) a new simple global…

Differential Geometry · Mathematics 2019-06-21 Radu Pantilie