English
Related papers

Related papers: Abundance for slc surfaces over arbitrary fields

200 papers

We give a systematic construction of uniruled surfaces in positive characteristic. Using this construction, we find surfaces of general type with non-trivial vector fields, surfaces with arbitrarily non-reduced Picard schemes as well as…

Algebraic Geometry · Mathematics 2008-05-27 Christian Liedtke

For an abelian variety over a finite field, Clozel (1999) showed that l-homological equivalence coincides with numerical equivalence for infinitely many l, and the author (1999) gave a criterion for the Tate conjecture to follow from Tate's…

Algebraic Geometry · Mathematics 2019-07-10 James S Milne

The Abundance conjecture predicts that on a minimal projective klt pair $(X,\Delta)$, the adjoint divisor $K_X+\Delta$ is semiample. When $\chi(X,\mathcal O_X)\neq0$, we give a necessary and sufficient condition for the conjecture to hold…

Algebraic Geometry · Mathematics 2024-06-27 Vladimir Lazić

The set of volumes of stable surfaces does have accumulation points. In this paper, we study this phenomenon for surfaces with one cyclic quotient singularity, towards answering the question under which conditions we can still have…

Algebraic Geometry · Mathematics 2021-07-06 Diana Torres

We show that Lang's hyperbolic and function version conjectures hold for surfaces $S$ of general type having a fibration of general type onto a curve $C$. The notion of multiplicity used is natural, but not classical, which leds to orbifold…

Algebraic Geometry · Mathematics 2007-05-23 Frédéric Campana

Working in the category of smooth projective varieties over an algebraically closed field of characteristic 0, we review notions of ampleness and numerical nefness for Higgs bundles which "feel" the Higgs field and formulate criteria of the…

Algebraic Geometry · Mathematics 2023-08-09 Ugo Bruzzo , Armando Capasso , Beatriz Graña Otero

Using Langer's construction of Bridgeland stability conditions on normal surfaces, we prove Reider-type theorems generalizing the work done by Arcara-Bertram in the smooth case. Our results still hold in positive characteristic or when…

Algebraic Geometry · Mathematics 2024-11-15 Anne Larsen , Anda Tenie

The aim of this work is to construct examples of pairs whose logarithmic cotangent bundles have strong positivity properties. These examples are constructed from any smooth n-dimensional complex projective varieties by considering the sum…

Algebraic Geometry · Mathematics 2017-12-29 Damian Brotbek , Ya Deng

We study statistical properties of a continuum model of polynuclear surface growth on an infinite substrate. We develop a self-consistent mean-field theory which is solved to deduce the growth velocity and the extremal behavior of the…

Statistical Mechanics · Physics 2009-10-30 E. Ben-Naim , A. R. Bishop , I. Daruka , P. L. Krapivsky

We show that Fujita's conjecture is true for quasi-elliptic surfaces. Explicitly, for any quasi-elliptic surface $X$ and an ample line bundle $A$ on $X$, we have $K_X + tA$ is base point free for $t \geq 3$ and is very ample for $t \geq 4$.

Algebraic Geometry · Mathematics 2022-02-24 Yen-An Chen

We define the over-exceptional lattice of a minimal algebraic surface of Kodaira dimension 0. Bounding the rank of this object, we prove that a conjecture by Campana and Corvaja--Zannier holds for Enriques surfaces, as well as K3 surfaces…

Algebraic Geometry · Mathematics 2023-01-18 Damián Gvirtz-Chen , Giacomo Mezzedimi

Given a logarithmic $1$-form on the snc locus of a log canonical surface pair $(X, D)$ over a perfect field of characteristic $p \ge 7$, we show that it extends with at worst logarithmic poles to any resolution of singularities. We also…

Algebraic Geometry · Mathematics 2022-01-19 Patrick Graf

We develop a formalism to extract triple crossing symmetric positivity bounds for effective field theories with multiple degrees of freedom, by making use of $su$ symmetric dispersion relations supplemented with positivity of the partial…

High Energy Physics - Theory · Physics 2026-02-09 Zong-Zhe Du , Cen Zhang , Shuang-Yong Zhou

The main result of the paper is a boundedness for $n$-complements on algebraic surfaces. In addition, applications of this theorem to a classification of log Del Pezzo surfaces and of birational contractions for 3-folds are formulated.

alg-geom · Mathematics 2007-05-23 V. V. Shokurov

This paper seeks to prove the bijectivity of the "Nash mapping" from the set of irreducible components of the scheme parametrizing analytic arcs on an algebraic surface $X$ whose origin is a singular point, into the set of irreducible…

Algebraic Geometry · Mathematics 2018-12-04 Augusto Nobile

We extend results on asymptotic invariants of line bundles on complex projective varieties to projective varieties over arbitrary fields. To do so over imperfect fields, we prove a scheme-theoretic version of the gamma construction of…

Algebraic Geometry · Mathematics 2021-05-11 Takumi Murayama

Let $(X,\Delta)$ be a normal pair with a projective morphism $X \to Z$ and let $A$ be a relatively ample $\mathbb{R}$-divisor on $X$. We prove the termination of some minimal model program on $(X,\Delta+A)/Z$ and the abundance conjecture…

Algebraic Geometry · Mathematics 2025-10-21 Kenta Hashizume

Very ampleness criteria for rank 2 vector bundles over smooth, ruled surfaces over rational and elliptic curves are given. The criteria are then used to settle open existence questions for some special threefolds of low degree.

Algebraic Geometry · Mathematics 2009-02-23 Alberto Alzati , GianMario Besana

We prove a general specialization theorem which implies stable irrationality for a wide class of quadric surface bundles over rational surfaces. As an application, we solve with the exception of two cases, the stable rationality problem for…

Algebraic Geometry · Mathematics 2018-05-23 Stefan Schreieder

We study $l$-very ample, ample and semi-ample divisors on the blown-up projective space $\mathbb{P}^n$ in a collection of points in general position. We establish Fujita's conjectures for all ample divisors with the number of points bounded…

Algebraic Geometry · Mathematics 2017-09-18 Olivia Dumitrescu , Elisa Postinghel