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

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A rigidity result for a class of compact generalized quasi-Einstein manifolds with constant scalar curvature is obtained. Moreover, under some geometric assumptions, the rigidity for the noncompact case is also proved. Considering non…

Differential Geometry · Mathematics 2021-12-09 Antonio Airton Freitas Filho , Keti Tenenblat

Let $M$ be a complete K\"ahler manifold with nonnegative bisectional curvature. Suppose the universal cover does not split and $M$ admits a nonconstant holomorphic function with polynomial growth, we prove $M$ must be of maximal volume…

Differential Geometry · Mathematics 2015-04-21 Gang Liu

The conullity of a curvature tensor is the codimension of its kernel. We consider the cases of conullity two in any dimension and conullity three in dimension four. We show that these conditions are compatible with non-negative sectional…

Differential Geometry · Mathematics 2021-12-01 Thomas G. Brooks

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

We consider a compact K\"ahler manifold admitting a constant scalar curvature K\"ahler metric and with no nontrivial holomorphic vector fields. After blowing up the manifold at finitely many points, we prove the existence of constant scalar…

Differential Geometry · Mathematics 2026-05-28 Yueqing Feng

We classify all smooth compact connected K\"ahler threefolds that admit the structure of a $C^\infty$-fiber bundle over the circle. This generalizes the work of Hao and Schreieder in the projective case. In contrast to the projective case,…

Algebraic Geometry · Mathematics 2025-06-30 Simon Pietig

We show that, under the definiteness of holomorphic sectional curvature, the spaces of some holomorphic tensor fields on compact Chern-K\"{a}hler-like Hermitian manifolds are trivial. These can be viewed as counterparts to Bochner's…

Differential Geometry · Mathematics 2024-09-06 Ping Li

The paper is part of an attempt of understanding non-K\"ahler threefolds. We start by looking at compact complex non-K\"ahler threefolds with algebraic dimension two and admitting locally conformally K\"ahler metrics. Under certain…

Differential Geometry · Mathematics 2023-03-21 Daniele Angella , Maurizio Parton , Victor Vuletescu

This paper is the first step in a systematic project to study examples of K\"ahler manifolds with positive holomorphic sectional curvature ($H > 0$). Previously Hitchin proved that any compact K\"ahler surface with $H>0$ must be rational…

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

We study the existence problem for complete contact forms with constant Tanaka--Webster scalar curvature on non-compact strictly pseudoconvex CR manifolds. We prove that, under mild assumptions, the universal cover of a compact strictly…

Differential Geometry · Mathematics 2026-02-04 Jeffrey S. Case , Yuya Takeuchi

In this paper, we prove that a compact K\"ahler manifold $X$ with pseudo-effective (resp. singular positively curved) tangent bundle admits a smooth (resp. locally constant) rationally connected fibration $\phi \colon X \to Y$ onto a finite…

Algebraic Geometry · Mathematics 2025-02-04 Shin-ichi Matsumura , Chenghao Qing

We study Nevanlinna theory on complete K\"ahler manifolds. As a consequence of the main result, we prove a defect relation of holomorphic mappings from complete K\"ahler manifolds of non-positive sectional curvature into complex projective…

Complex Variables · Mathematics 2021-06-17 Xianjing Dong

In this short note, as a simple application of the strong result proved recently by B\"ohm and Wilking, we give a classification on closed manifolds with 2-nonnegative curvature operator. Moreover, by the new invariant cone constructions of…

Differential Geometry · Mathematics 2007-05-23 Lei Ni , Baoqiang Wu

We give a classification of many closed Riemannian manifolds M whose universal cover possesses a nontrivial amount of symmetry. More precisely, we consider closed Riemannian manifolds $M$ such that Isom$(\widetilde{M})$ has noncompact…

Differential Geometry · Mathematics 2014-05-12 Wouter van Limbeek

In this note we begin a systematic study of compact conformal manifolds of SCFTs in four dimensions (our notion of compactness is with respect to the topology induced by the Zamolodchikov metric). Supersymmetry guarantees that such…

High Energy Physics - Theory · Physics 2015-06-23 Matthew Buican , Takahiro Nishinaka

In this article we prove a theorem of Ohsawa-Takegoshi type on compact K\"ahler manifolds. Our arguments follow the "standard" approach for this kind of extension results; however, there are many complications arising from the…

Algebraic Geometry · Mathematics 2011-04-18 Li Yi

In this paper we show an abundance of complete K\"ahler metrics with negative holomorphic bisectional curvature on total spaces of certain vector bundles. Assume that such total spaces are endowed with a wider class of nonpositively curved…

Differential Geometry · Mathematics 2025-11-18 Hanyu Wu , Bo Yang

We show that a space with a finite asymptotic dimension is embeddable in a non-positively curved manifold. Then we prove that if a uniformly contractible manifold X is uniformly embeddable in $\R^n$ or non-positively curved n-dimensional…

Geometric Topology · Mathematics 2007-05-23 A. N. Dranishnikov

We show that if the universal cover of a closed smooth manifold admitting a metric with non-negative Ricci curvature is formal, then the manifold itself is formal. We reprove a result of Fiorenza-Kawai-L\^e-Schwachh\"ofer, that closed…

Differential Geometry · Mathematics 2024-07-01 Aleksandar Milivojevic

Let $G/H$ be a closed, simply connected homogeneous manifold. Suppose every stable class of real vector bundles over $G/H$ contains a homogeneous bundle. Then, for any closed, simply connected smooth manifold $M$ homotopy equivalent to…

Differential Geometry · Mathematics 2025-08-22 Wen Shen