English
Related papers

Related papers: Projectively flat KLT varieties

200 papers

We give a criterion for the projectivisation of a reflexive sheaf on a klt space to be induced by a projective representation of the fundamental group of the smooth locus. This criterion is then applied to give a characterisation of finite…

Algebraic Geometry · Mathematics 2022-07-25 Daniel Greb , Stefan Kebekus , Thomas Peternell

We study degenerations of complex projective spaces $\mathbb P^n$ into normal projective klt varieties $X$. If the tangent sheaf of $X$ is semi-stable, we show that $X$ itself is a projective space. If $X$ is a threefold with canonical…

Algebraic Geometry · Mathematics 2024-07-19 Andreas Höring , Thomas Peternell

In this paper, we extend the structure theorem for smooth projective varieties with nef tangent bundle to projective klt varieties whose tangent sheaf is either positively curved or almost nef. Specifically, we show that such a variety $X$,…

Algebraic Geometry · Mathematics 2025-07-23 Masataka Iwai , Shin-ichi Matsumura , Guolei Zhong

We prove that the tangent and the reflexivized cotangent sheaves of any normal projective klt Calabi-Yau or irreducible holomorphic symplectic variety are not pseudoeffective, generalizing results of A. H\"oring and T. Peternell…

Algebraic Geometry · Mathematics 2024-12-16 Cécile Gachet

In this paper, we prove that a smooth projective globally $F$-split variety with numerically flat tangent bundle is an \'etale quotient of an ordinary abelian variety. We also show its logarithmic analog, which contains a characterization…

Algebraic Geometry · Mathematics 2023-03-20 Sho Ejiri , Shou Yoshikawa

We consider the category $\operatorname{Qcoh}\mathbb{X}$ of quasicoherent sheaves where $\mathbb{X}$ is a weighted noncommutative regular projective curve over a field $k$. This category is a hereditary, locally noetherian Grothendieck…

Representation Theory · Mathematics 2020-09-28 Dirk Kussin , Rosanna Laking

In this article, we study $G$-covers of klt varieties, where $G$ is a reductive group. First, we exhibit an example of a klt singularity admitting a $\mathbb{P}{\rm GL}_n(\mathbb{K})$-cover that is not of klt type. Then, we restrict…

Algebraic Geometry · Mathematics 2022-10-20 Lukas Braun , Joaquín Moraga

We extend Orlov's representability theorem on the equivalence of derived categories of sheaves to the case of smooth stacks associated to normal projective varieties with only quotient singularities.

Algebraic Geometry · Mathematics 2007-05-23 Yujiro Kawamata

The geometric and algebraic properties of smooth projective varieties with 1-regular structure sheaf are well understood, and the complete classification of these varieties is a classical result. The aim of this paper is to study the next…

Algebraic Geometry · Mathematics 2018-03-06 Sijong Kwak , Jinhyung Park

Ball quotients, hyperelliptic varieties, and projective spaces are characterized by their Chern classes, as the varieties where the Miyaoka-Yau inequality becomes an equality. Ball quotients, Abelian varieties, and projective spaces are…

Algebraic Geometry · Mathematics 2024-07-16 Daniel Greb , Stefan Kebekus , Thomas Peternell

Semisimple representations of the free product Z_p*Z_q determine \theta-semistable representations of a specific quiver Q_pq. The dimension vectors of \theta-stable representations of this quiver were classified by Le Bruyn and…

Algebraic Geometry · Mathematics 2007-05-23 Jan Adriaenssens , Raf Bocklandt , Geert Van de Weyer

We give a criterion for the sheaf of K\"ahler differentials on a cone over a smooth projective variety to be torsion-free. Applying this to Veronese embeddings of projective space and using known results on differentials on quotient…

Algebraic Geometry · Mathematics 2015-04-17 Daniel Greb , Sönke Rollenske

Projective structures on compact real manifolds are classical objects in real differential geometry. Complex manifolds with a holomorphic projective structure on the other hand form a special class as soon as the dimension is greater than…

Algebraic Geometry · Mathematics 2015-03-02 Priska Jahnke , Ivo Radloff

This paper extends a number of known results on slope-semistable sheaves from the classical case to the setting where polarisations are given by movable curve classes. As applications, we obtain new flatness results for reflexive sheaves on…

Algebraic Geometry · Mathematics 2016-06-28 Daniel Greb , Stefan Kebekus , Thomas Peternell

We show that a smooth projective variety admits a Chow-Kunneth decomposition if the cohomology has level at most one except for the middle degree. This can be extended to the relative case in a weak sense if the morphism has only isolated…

Algebraic Geometry · Mathematics 2007-05-23 Morihiko Saito

It is given the diffeomorphism classification on generic singularities of tangent varieties to curves with arbitrary codimension in a projective space. The generic classifications are performed in terms of certain geometric structures and…

Differential Geometry · Mathematics 2012-02-16 Goo Ishikawa

In this paper, we develop a theory of pseudo-effective sheaves on normal projective varieties. As an application, by running the minimal model program, we show that projective klt varieties with pseudo-effective tangent sheaf can be…

Algebraic Geometry · Mathematics 2026-05-27 Shin-ichi Matsumura

We investigate the holonomy group of singular K\"ahler-Einstein metrics on klt varieties with numerically trivial canonical divisor. Finiteness of the number of connected components, a Bochner principle for holomorphic tensors, and a…

Algebraic Geometry · Mathematics 2020-06-16 Daniel Greb , Henri Guenancia , Stefan Kebekus

This article is motivated by the following local-to-global question: is every variety with tame quotient singularities globally the quotient of a smooth variety by a finite group? We show that this question has a positive answer for all…

Algebraic Geometry · Mathematics 2015-12-01 Anton Geraschenko , Matthew Satriano

Let $\mathbb{X}$ be a weighted noncommutative regular projective curve over a field $k$. The category $\operatorname{Qcoh}\mathbb{X}$ of quasicoherent sheaves is a hereditary, locally noetherian Grothendieck category. We classify all…

Algebraic Geometry · Mathematics 2017-02-09 Lidia Angeleri Hügel , Dirk Kussin
‹ Prev 1 2 3 10 Next ›