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Related papers: Algebraic approximation of K\"ahler threefolds

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In this article, we study some properties of deformation invariance of the Gamma-dimension (defined for X a compact k\"ahler manifold). This birational invariant is defined as the codimension of the maximal compact subvarieties in the…

Algebraic Geometry · Mathematics 2014-10-13 Benoît Claudon

We study the geometry of exceptional loci of birational contractions of hyper-K\"ahler fourfolds that are of K3$^{[2]}$-type. These loci are conic bundles over K3 surfaces and we determine their classes in the Brauer group. For this we use…

Algebraic Geometry · Mathematics 2022-12-12 Bert van Geemen , Grzegorz Kapustka

Concerning the problem of classifying complete submanifolds of Euclidean space with codimension two admitting genuine isometric deformations, until now the only known examples with the maximal possible rank four are the real Kaehler minimal…

Differential Geometry · Mathematics 2018-08-22 M. Dajczer , Th. Vlachos

We prove that a smooth complex projective threefold with a K\"ahler metric of negative holomorphic sectional curvature has ample canonical line bundle. In dimensions greater than three, we prove that, under equal assumptions, the nef…

Algebraic Geometry · Mathematics 2009-09-02 Gordon Heier , Steven S. Y. Lu , Bun Wong

We investigate when the tangent bundle of a projective manifold has a non-trivial first order (or positive-dimensional) deformation. This leads to a new conjectural characterization of the complex projective space.

Algebraic Geometry · Mathematics 2020-07-20 Thomas Peternell

For a quasi-compact K\"ahler manifold $U$ endowed with a nilpotent harmonic bundle whose Higgs field is injective at one point, we prove that $U$ is pseudo-algebraically hyperbolic, pseudo-Picard hyperbolic, and is of log general type.…

Algebraic Geometry · Mathematics 2021-07-19 Benoît Cadorel , Ya Deng

The first part of this paper discusses general procedures for finding numerical approximations to distinguished Kahler metrics, such as Calabi-Yau metrics, on complex projective manifolds. These procedures are closely related to ideas from…

Differential Geometry · Mathematics 2007-05-23 S. K. Donaldson

We study the existence of canonical K\"ahler metrics on the projectivisation of strictly Mumford semistable holomorphic vector bundles over a complex curve. We also provide an algebro-geometric characterization of these metrics.

Differential Geometry · Mathematics 2017-05-17 Julien Keller

We apply the method of algebraic deformation to N-tuple of algebraic K3 surfaces. When N=3, we show that the deformed triplet of algebraic K3 surfaces exhibits a deformed hyperk\"{a}hler structure. The deformation moduli space of this…

High Energy Physics - Theory · Physics 2007-05-23 Chang-Yeong Lee

Motivated by the geometry of Levi degenerate CR hypersurfaces, we define a pre-K\"ahler structure on a complex manifold as a pre-symplectic structure compatible with the almost complex structure, i.e. a closed (1,1)-form. Extending Freeman…

Differential Geometry · Mathematics 2025-05-16 Omid Makhmali , David Sykes

In this paper we propose and investigate in full generality new notions of (continuous, non-isometric) symmetry on hyperk\"ahler spaces. These can be grouped into two categories, corresponding to the two basic types of continuous…

Differential Geometry · Mathematics 2019-07-17 Radu A. Ionas

This paper is concerned with restricted families of projections in $\mathbb{R}^{3}$. Let $K \subset \mathbb{R}^{3}$ be a Borel set with Hausdorff dimension $\dim K = s > 1$. If $\mathcal{G}$ is a smooth and sufficiently well-curved…

Classical Analysis and ODEs · Mathematics 2016-02-03 Tuomas Orponen

In the first part we survey some of the known results and conjectures on compact Hyperkaehler (HK) manifolds. In the second part we presents a program which aims to show that HK four-folds whose second cohomology (with 4-tuple cup-product)…

Algebraic Geometry · Mathematics 2010-05-19 Kieran G. O'Grady

We present a simple geometric construction linking geometric to deformation quantization. Both theories depend on some apparently arbitrary parameters, most importantly a polarization and a symplectic connection, and for real polarizations…

Mathematical Physics · Physics 2009-07-06 Christoph Nölle

We derive algebraic recurrence relations to obtain a deformation quantization with separation of variables for a locally symmetric K\"ahler manifold. This quantization method is one of the ways to perform a deformation quantization of…

Mathematical Physics · Physics 2020-07-07 Kentaro Hara , Akifumi Sako

We study triples of graded rings defined over the deformation spaces for certain one-parameter families of Calabi-Yau threefolds. These rings are analogues of the rings of modular forms, quasi-modular forms and almost-holomorphic modular…

High Energy Physics - Theory · Physics 2014-11-27 Jie Zhou

Twistor spaces are certain compact complex threefolds with an additional real fibre bundle structure. We focus here on twistor spaces over $3\mathbb{C}\mathbb{P}^2$. Such spaces are either small resolutions of double solids or they can be…

Algebraic Geometry · Mathematics 2026-02-16 Bernd Kreussler , Jan Stevens

We classify non-algebraic compact K\"ahler threefolds admitting an endomorphism $f: X \to X$ of degree at least two.

Algebraic Geometry · Mathematics 2017-11-10 Andreas Höring , Thomas Peternell

The aim of these notes is to acquaint the reader with important objects in complex algebraic geometry: K3 surfaces and their higher-dimensional analogs, hyperk\"ahler manifolds. These manifolds are interesting from several points of view:…

Algebraic Geometry · Mathematics 2020-11-18 Olivier Debarre

Let $\pi\cln X\to \Delta^m$ be a proper smooth K\"ahler morphism from a complex manifold $X$ to the unit polydisc $\Delta^m$. Suppose the fibers over the complement of a proper analytic subset are biholomorphic to a fixed projective…

Algebraic Geometry · Mathematics 2026-05-11 Mu-Lin Li , Xiao-Lei Liu