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Related papers: Effective base point free theorem for log canonica…

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We prove Koll\'ar's effective base point free theorem for log canonical pairs.

Algebraic Geometry · Mathematics 2009-07-13 Osamu Fujino

We prove the Angehrn-Siu Type effective freeness and effective point separation for quasi-log canonical pairs. As a natural consequence, we obtain that these two results hold for semi-log canonical pairs. One of the main ingredients of our…

Algebraic Geometry · Mathematics 2019-07-17 Haidong Liu

We prove Koll\'ar-type effective basepoint-free theorems for quasi-log canonical pairs.

Algebraic Geometry · Mathematics 2016-11-24 Osamu Fujino

We prove a base point free theorem for nef and log big divisors on log canonical surfaces.

alg-geom · Mathematics 2008-02-03 Shigetaka Fukuda

We obtain a correct generalization of Shokurov's non-vanishing theorem for log canonical pairs. It implies the base point free theorem for log canonical pairs. We also prove the rationality theorem for log canonical pairs. As a corollary,…

Algebraic Geometry · Mathematics 2009-12-01 Osamu Fujino

We prove the base point free theorem for big line bundles on a three-dimensional log canonical projective pair defined over the algebraic closure of a finite field.

Algebraic Geometry · Mathematics 2016-01-20 Diletta Martinelli , Yusuke Nakamura , Jakub Witaszek

This paper proposes a Fujita-type freeness conjecture for semi-log canonical pairs. We prove it for curves and surfaces by using the theory of quasi-log schemes and give some effective very ampleness results for stable surfaces and semi-log…

Algebraic Geometry · Mathematics 2017-01-26 Osamu Fujino

We reformulate base point free theorems. Our formulation is flexible and has some important applications. One of the main purposes of this paper is to prove a generalization of the base point free theorem in Fukuda's paper: On numerically…

Algebraic Geometry · Mathematics 2011-02-18 Osamu Fujino

In this paper, we establish a basepoint free theorem of Angehrn-Siu type in positive characteristic. Moreover, we also give an effective bound for very ampleness in arbitrary characteristic.

Algebraic Geometry · Mathematics 2013-04-03 Hiromu Tanaka

We prove the special termination for log canonical pairs and its generalisation in the context of generalised pairs.

Algebraic Geometry · Mathematics 2023-12-14 Vladimir Lazić , Joaquín Moraga , Nikolaos Tsakanikas

We prove the base point free theorem for log canonical foliated pairs of rank one on a Q-factorial projective klt threefold. Moreover, we show abundance in the case of numerically trivial log canonical foliated pairs of rank one in any…

Algebraic Geometry · Mathematics 2026-01-21 Paolo Cascini , Calum Spicer

We prove that every quasi-projective semi log canonical pair has a quasi-log structure with several good properties. It implies that various vanishing theorems, torsion-free theorem, and the cone and contraction theorem hold for semi log…

Algebraic Geometry · Mathematics 2013-10-29 Osamu Fujino

We prove the abundance theorem for numerically trivial log canonical divisors of log canonical pairs and semi-log canonical pairs.

Algebraic Geometry · Mathematics 2010-09-14 Yoshinori Gongyo

The authors and D. Martinelli proved the base point free theorem for big line bundles on a three-dimensional log canonical projective pair defined over the algebraic closure of a finite field. In this paper, we drop the bigness condition…

Algebraic Geometry · Mathematics 2024-04-30 Yusuke Nakamura , Jakub Witaszek

We describe the foundation of the log minimal model program for log canonical pairs according to Ambro's idea. We generalize Koll\'ar's vanishing and torsion-free theorems for embedded simple normal crossing pairs. Then we prove the cone…

Algebraic Geometry · Mathematics 2009-07-10 Osamu Fujino

Let $(X,\Delta)$ be a proper dlt pair and $L$ a nef Cartier divisor such that $aL-(K_X+\Delta)$ is nef and log big on $(X,\Delta)$ for some $a\in {\mathbb Z}_{>0}$. Then $|mL|$ is base point free for every $m\gg 0$.

Algebraic Geometry · Mathematics 2007-05-23 Osamu Fujino

This paper is a gentle introduction to the theory of quasi-log varieties by Ambro. We explain the fundamental theorems for the log minimal model program for log canonical pairs. More precisely, we give a proof of the base point free theorem…

Algebraic Geometry · Mathematics 2009-10-25 Osamu Fujino

We establish a relative spannedness for log canonical pairs, which is a generalization of the basepoint-freeness for varieties with log-terminal singularities by Andreatta--Wi\'sniewski. Moreover, we establish a generalization for quasi-log…

Algebraic Geometry · Mathematics 2020-12-01 Osamu Fujino

We prove Fujita-type basepoint-freeness for projective quasi-log canonical curves and surfaces.

Algebraic Geometry · Mathematics 2020-12-23 Osamu Fujino , Haidong Liu

We apply Angehrn-Siu-Helmke's method to estimate basepoint freeness thresholds of higher dimensional polarized abelian varieties. We showed that a conjecture of Caucci holds for very general polarized abelian varieties in the moduli spaces…

Algebraic Geometry · Mathematics 2022-07-12 Zhi Jiang
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