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Suppose that $X$ is a projective manifold whose tangent bundle $T_X$ contains a locally free strictly nef subsheaf. We prove that $X$ is isomorphic to a projective bundle over a hyperbolic manifold. Moreover, if the fundamental group…

Algebraic Geometry · Mathematics 2020-04-21 Jie Liu , Wenhao Ou , Xiaokui Yang

We prove Kov\'acs' conjecture that claims that if the $p^{th}$ exterior power of the tangent bundle of a smooth complex projective variety contains the $p^{th}$ exterior power of an ample vector bundle then the variety is either projective…

Algebraic Geometry · Mathematics 2026-02-02 Soham Ghosh

In this note we prove that any toric Fano manifold with nef tangent bundle is a product of projective spaces. In particular, it implies that Campana-Peternell conjecture hold for toric manifolds.

Algebraic Geometry · Mathematics 2015-06-19 Qilin Yang

Junyan Cao has obtained a very general vanishing theorem, valid on any compact K\"ahler manifold, for the cohomology groups with values in a pseudoeffective line bundle twisted by the associated multiplier ideal sheaf. In this note, we give…

Algebraic Geometry · Mathematics 2020-11-30 Xiaojun Wu

We provide several results on the existence of metrics of non-negative sectional curvature on vector bundles over certain cohomogeneity one manifolds and homogeneous spaces up to suitable stabilization. Beside explicit constructions of the…

Differential Geometry · Mathematics 2022-05-09 Manuel Amann , David González-Álvaro , Marcus Zibrowius

We propose, motivate and give evidence for a relation between the $\mathcal D$-modules of the quantum cohomology of a smooth complex projective manifold $X$ and a projective bundle $\PP(\oplus L_i)$ over $X$.

Algebraic Geometry · Mathematics 2007-05-23 Artur Elezi

We give a proof of the openness conjecture of Demailly and Koll\'ar for positively curved singular metrics on ample line bundles over projective varieties. As a corollary it follows that the openness conjecture for plurisubharmonic…

Complex Variables · Mathematics 2013-05-14 Bo Berndtsson

In this article, we investigate the stability of syzygy bundles corresponding to ample and globally generated vector bundles on smooth irreducible projective surfaces.

Algebraic Geometry · Mathematics 2024-05-28 Snehajit Misra , Nabanita Ray

The doubling conjecture predicts that a manifold admits positive scalar curvature with mean convex boundary if and only if its double admits positive scalar curvature. We show that it holds true for manifolds where the inclusion of the…

Differential Geometry · Mathematics 2026-04-15 Georg Frenck

We examine the bundle structure of the field of nowhere vanishing null vector fields on a (time-oriented) Lorentzian manifold. Sections of what we refer to as the null tangent, are by definition nowhere vanishing null vector fields. It is…

Differential Geometry · Mathematics 2022-09-21 Andrew James Bruce

Proven by A. Parshin and S. Arakelov in the early 70's, Shafaverich hyperbolicity conjecture states that a family of curves of genus $g\ge2$ parametrized by a non hyperbolic curve (\emph{i.e.} isomorphic to $\mathbb{P}^1$, $\mathbb{C}$,…

Algebraic Geometry · Mathematics 2016-04-01 Benoît Claudon

The algebraic approach to bundles in non-commutative geometry and the definition of quantum real weighted projective spaces are reviewed. Principal U(1)-bundles over quantum real weighted projective spaces are constructed. As the spaces in…

Quantum Algebra · Mathematics 2012-07-11 Tomasz Brzeziński , Simon A. Fairfax

Chow's Theorem and GAGA are renowned results demonstrating the algebraic nature of projective manifolds and, more broadly, projective analytic varieties. However, determining if a particular manifold is projective is not, generally, a…

Algebraic Geometry · Mathematics 2025-01-14 Skyler Marks

We consider positivity properties of vector bundles over conic neighbourhoods of sections of submersions over $1$-convex manifolds.

Complex Variables · Mathematics 2017-01-19 Jasna Prezelj

We prove that a compact Hermitian manifold with semi-positive but not identically zero holomorphic sectional curvature has Kodaira dimension $-\infty$. As applications, we show that Kodaira surfaces and hyperelliptic surfaces can not admit…

Differential Geometry · Mathematics 2016-04-14 Xiaokui Yang

In this paper we prove the following result : if the p-th tensor power of the tangent bundle of a smooth projective variety contains the p-th power of an ample line bundle, then the variety is isomorphic either to the projective space or to…

Algebraic Geometry · Mathematics 2010-09-13 Matthieu Paris

A conjecture of Batyrev and Manin predicts the asymptotic behaviour of rational points of bounded height on smooth projective varieties over number fields. We prove some new cases of this conjecture for conic bundle surfaces equipped with…

Number Theory · Mathematics 2020-09-08 Christopher Frei , Daniel Loughran

We study the relations between the triviality of the tangent bundle $TM$ and the generalized tangent bundle $\mathbb{T}M = TM\oplus T^*M$ of a manifold. We show that the generalized tangent bundle of a paralellizable manifold is trivial. We…

Differential Geometry · Mathematics 2026-05-18 Fernando Etayo , Pablo Gómez-Nicolás , Rafael Santamaría

We study the Euler class of smooth orientable infinite-type surface bundles with a section. For many such surfaces, we show that this cohomology class is nontrivial, and that the behavior of its powers depends on the genus and the type of…

Geometric Topology · Mathematics 2025-09-26 Mauricio Bustamante , Rita Jiménez Rolland , Israel Morales

The Hartshorne conjecture predicts that two submanifolds X and Y in a projective manifold Z with ample normal bundles meets as soon as dim X + dim Y is at least dim Z. We mostly assume slightly stronger that one of the normal bundles is…

Algebraic Geometry · Mathematics 2008-04-08 Thomas Peternell