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Related papers: Abundance for Kaehler threefolds

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For every compact K\"ahler manifold $X$ of algebraic dimension $a(X) = \dim X - 1$, we prove that $X$ has arbitrarily small deformations to some projective manifolds.

Algebraic Geometry · Mathematics 2020-12-16 Hsueh-Yung Lin

We construct examples of complete quaternionic K\"ahler manifolds with an end of finite volume, which are not locally homogeneous. The manifolds are aspherical with fundamental group which is up to an infinite cyclic extension a semi-direct…

Differential Geometry · Mathematics 2022-12-23 V. Cortés , M. Röser , D. Thung

We show that for a weak $\mathbb{Q}$-Fano threefold $X$ ($\mathbb{Q}$-factorial with terminal singularities and $-K_X$ is nef and big) of Picard rank $\rho(X)\leq 2$, either $-K_X^3\leq 64$ or $-K_X^3=72$ and…

Algebraic Geometry · Mathematics 2025-02-28 Ching-Jui Lai , Tsung-Ju Lee

A necessary and sufficient condition is given for semi-ampleness of a numerically effective (nef) and big line bundle in positive characteristic. One application is to the geometry of the universal stable curve over M_g, specifically, the…

Algebraic Geometry · Mathematics 2016-09-07 Seán Keel

We study degenerate complex Monge-Amp\`ere equations of the form $(\omega+dd^c \varphi)^n = e^{t \varphi} \mu$ where $\omega$ is a big semi-positive form on a compact K\"ahler manifold $X$ of dimension $n$, $t \in \R^+$, and $\mu=f\omega^n$…

Algebraic Geometry · Mathematics 2008-09-24 Philippe Eyssidieux , Vincent Guedj , Ahmed Zeriahi

The goal of this work is give a precise numerical description of the K\"ahler cone of a compact K\"ahler manifold. Our main result states that the K\"ahler cone depends only on the intersection form of the cohomology ring, the Hodge…

Algebraic Geometry · Mathematics 2007-05-23 Jean-Pierre Demailly , Mihai Paun

We consider Fano threefolds $X$ with canonical Gorenstein singularities. Under additional assumption that $X$ has at least one non-cDV point we prove a sharp bound of the degree: $-K_X^3\le 72$.

Algebraic Geometry · Mathematics 2010-05-12 Yuri G. Prokhorov

Let $X$ be a compact K\"ahler manifold and let $(L, \varphi)$ be a pseudo-effective line bundle on $X$. We first define a notion of numerical dimension of pseudo-effective line bundles with singular metrics, and then discuss the properties…

Algebraic Geometry · Mathematics 2019-02-20 Junyan Cao

A complex manifold $X$ of dimension $n$ together with an ample vector bundle $E$ on it will be called a {\sf generalized polarized variety}. The adjoint bundle of the pair $(X,E)$ is the line bundle $K_X + det(E)$. We study the positivity…

alg-geom · Mathematics 2015-06-30 M. Andreatta , M. Mella

We prove that if the fundamental group of an arbitrary three-manifold -- not necessarily closed, nor orientable -- is a Kaehler group, then it is either finite or the fundamental group of a closed orientable surface.

Geometric Topology · Mathematics 2014-01-14 D. Kotschick

We show that a compact Kaehler manifold X is a complex torus if both the continuous part and discrete part of some automorphism group G of X are infinite groups, unless X is bimeromorphic to a non-trivial G-equivariant fibration. Some…

Algebraic Geometry · Mathematics 2018-09-24 Baohua Fu , De-Qi Zhang

This paper shows that for K a local field, k a subfield of K and X a variety over k, X is complete if and only if for every finite field extension K' of K, X(K') is compact in its strong topology.

Algebraic Geometry · Mathematics 2007-05-23 Oliver Lorscheid

In this paper we give sufficient conditions on a compact orbifold with an extremal Kaehler metric to admit a resolution with an extremal Kaehler metric. We also complete the Kaehler constant scalar curvature case.

Differential Geometry · Mathematics 2015-07-17 Claudio Arezzo , Riccardo Lena , Lorenzo Mazzieri

In this article we are mainly concerned with three dimensional compact K\"ahler spaces with log terminal singularities. We establish the orbifold version of the Bogomolov-Gieseker inequality for stable $\mathbb Q$-sheaves.

Algebraic Geometry · Mathematics 2025-03-04 Henri Guenancia , Mihai Păun

Let $(V,\omega)$ be a compact K\"ahler manifold such that $V$ admits a cover by Zariski-open Stein sets with the property that $\omega$ has a strictly plurisubharmonic exhaustive potential on each element of the cover. If $X\subset V$ is an…

Complex Variables · Mathematics 2022-04-05 Dan Coman , Vincent Guedj , Ahmed Zeriahi

This master's thesis contains an introduction to $A_\infty$-algebras and homological perturbation theory. We then discuss the formality of compact K\"ahler manifolds and present a direct proof of a homotopy transfer principle of…

Rings and Algebras · Mathematics 2021-07-08 Carl Felix Waller

A celebrated conjecture of Kobayashi and Lang says that the canonical line bundle $K_X$ of a Kobayashi hyperbolic compact complex manifold $X$ is ample. In this note we prove that $K_X$ is ample if $X$ is projective and satisfies a stronger…

Algebraic Geometry · Mathematics 2017-09-05 Aleksei Golota

This paper establishes the existence of a finitely based finite semiring whose variety contains a continuum of subvarieties; such a variety is said to be of type \(2^{\aleph_0}\). Using the homomorphism theory of Kneser graphs, we prove…

Rings and Algebras · Mathematics 2026-03-03 Zidong Gao

We prove an extension theorem for Kahler currents with analytic singularities in a Kahler class on a complex submanifold of a compact Kahler manifold.

Complex Variables · Mathematics 2014-10-10 Tristan C. Collins , Valentino Tosatti

Let $\mathcal{E}$ be an ample vector bundle of rank $r\geq 2$ on a smooth complex projective variety $X$ of dimension $n$. The aim of this paper is to describe the structure of pairs $(X,\mathcal{E})$ as above whose adjoint bundles…

Algebraic Geometry · Mathematics 2011-08-24 Andrea Luigi Tironi
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