English
Related papers

Related papers: Cone theorem and Mori hyperbolicity

200 papers

In this article, we introduce a new approach to show the existence and smoothing of simple normal crossing varieties in a given projective space. Our approach relates the above to the existence of nowhere reduced schemes called ribbons and…

Algebraic Geometry · Mathematics 2024-03-08 Purnaprajna Bangere , Francisco Javier Gallego , Jayan Mukherjee

We give a general formula for generators of the NL-cone, the cone of effective linear combinations of irreducible components of Noether-Lefschetz divisors, on an orthogonal modular variety. We then fully describe the NL-cone and its…

Algebraic Geometry · Mathematics 2025-11-26 Ignacio Barros , Pietro Beri , Laure Flapan , Brandon Williams

We construct a moduli space of stable projective pairs with a nontrivial action of a connected reductive group. These stable reductive pairs are higher-dimensional analogs of stable n-pointed curves and generalize to the non-commutative…

Algebraic Geometry · Mathematics 2007-05-23 Valery Alexeev , Michel Brion

Using the theory of moduli of curves, we establish various slope inequalities for general fibered surfaces. More precisely, we introduce the notion of functorial divisors on Artin stacks and prove a theorem concerning their effectiveness.…

Algebraic Geometry · Mathematics 2023-09-14 Makoto Enokizono

For every $r\in\mathbb{N}_{\geq 2}\cup\{\infty\}$, we prove a $C^r$-orbit connecting lemma for dynamically coherent and plaque expansive partially hyperbolic diffeomorphisms with 1-dimensional orientation preserving center bundle. To be…

Dynamical Systems · Mathematics 2023-09-06 Yi Shi , Xiaodong Wang

We prove that topologically conjugate non-renormalizable polynomials are quasi-conformally conjugate. From this we derive that each such polynomial can be approximated by a hyperbolic polynomial. As a by product we prove that the Julia set…

Dynamical Systems · Mathematics 2014-02-26 Oleg Kozlovski , Sebastian van Strien

Given a very ample line bundle on a smooth projective variety, the variation of Hodge structure associated to the universal family of hyperplane sections can be thought of as a $D$-module with action generated by the Gauss-Manin connection.…

Algebraic Geometry · Mathematics 2022-09-29 Daniel Brogan

In this paper, we study a projective klt pair $(X, \Delta)$ with the nef anti-log canonical divisor $-(K_X+\Delta)$ and its maximally rationally connected fibration $\psi: X \dashrightarrow Y$. We prove that the numerical dimension of the…

Algebraic Geometry · Mathematics 2019-10-16 Frédéric Campana , Junyan Cao , Shin-ichi Matsumura

We introduce the notion of quasi-log complex analytic spaces and establish various fundamental properties. Moreover, we prove that a semi-log canonical pair naturally has a quasi-log complex analytic space structure. This paper is part of…

Algebraic Geometry · Mathematics 2025-02-04 Osamu Fujino

In this paper we show that the global (log) canonical threshold of $d$-sheeted covers of the $M$-dimensional projective space of index 1, where $d\geqslant 4$, is equal to one for almost all families (except for a finite set). The varieties…

Algebraic Geometry · Mathematics 2019-06-28 Aleksandr V. Pukhlikov

In the case of toric varieties, we continue the pursuit of Kontsevich's fundamental insight, Homological Mirror Symmetry, by unifying it with the Mori program. We give a refined conjectural version of Homological Mirror Symmetry relating…

Algebraic Geometry · Mathematics 2013-02-05 Matthew Ballard , Colin Diemer , David Favero , Ludmil Katzarkov , Gabriel Kerr

We construct log resolutions of pairs on the blow-up of the projective space in an arbitrary number of general points and we discuss the semi-ampleness of the strict transforms. As an application we prove that the abundance conjecture holds…

Algebraic Geometry · Mathematics 2019-04-08 Olivia Dumitrescu , Elisa Postinghel

Let X be a projective variety which is algebraic Lang hyperbolic. We show that Lang's conjecture holds (one direction only): X and all its subvarieties are of general type and the canonical divisor K_X is ample at smooth points and Kawamata…

Algebraic Geometry · Mathematics 2019-07-08 Fei Hu , Sheng Meng , De-Qi Zhang

The main result is that a quasi-projective surface has negative log Kodaira dimension (i.e. no log pluricanonical sections) iff it is dominated by images of the affine line. This follows from our main intermediate result, that the smooth…

alg-geom · Mathematics 2008-02-03 Sean Keel , James McKernan

We prove that in any strictly convex symmetric cone $\Omega$ there exists a non empty locus where the WDVV equation is satisfied (i.e. there exists a hyperplane being a Frobenius manifold). This result holds over any real division algebra…

Algebraic Geometry · Mathematics 2023-09-11 Noemie C. Combe

We prove the existence of a Mori contraction on a compact Kaehler threefold whose canonical bundle is (analytically) not nef if the threefold can be approximated by projective threefolds or if the algebraic dimension is 2.

Algebraic Geometry · Mathematics 2007-05-23 Thomas Peternell

We study hyperbolicity for quasi-projective varieties where the boundary divisor consists of n+1 numerically parallel effective divisors on a complex projective variety of dimension n, allowing non-empty intersection. Under explicit local…

Complex Variables · Mathematics 2026-03-16 Julie Tzu-Yueh Wang , Zheng Xiao

Let X be a smooth Mori dream space of dimension at least 4. We show that, if X satisfies a suitable GIT condition which we call "small unstable locus", then every smooth ample divisor Y of X is also a Mori dream space. Moreover, the…

Algebraic Geometry · Mathematics 2010-01-07 Shin-Yao Jow

The goal of this work is to study positivity of subvarieties with nef normal bundle in the sense of intersection theory. After Ottem's work on ample subschemes, we introduce the notion of a nef subscheme, which generalizes the notion of a…

Algebraic Geometry · Mathematics 2019-07-10 Chung-Ching Lau

Given a real algebraic curve in the projective 3-space, its hyperbolicity locus is the set of lines with respect to which the curve is hyperbolic. We give an example of a smooth irreducible curve whose hyperbolicity locus is disconnected…

Algebraic Geometry · Mathematics 2024-12-04 Stepan Orevkov