English
Related papers

Related papers: Effective basepoint-free theorem for semi-log cano…

200 papers

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

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

In this paper, we show that Fujita's basepoint-freeness conjecture for projective quasi-log canonical singularities holds true in dimension three. Immediately, we prove Fujita-type basepoint-freeness for projective semi-log canonical…

Algebraic Geometry · Mathematics 2019-02-25 Haidong Liu

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

Algebraic Geometry · Mathematics 2016-11-24 Osamu Fujino

We introduce various new operations for quasi-log structures. Then we prove the basepoint-free theorem of Reid--Fukuda type for quasi-log schemes as an application.

Algebraic Geometry · Mathematics 2015-07-21 Osamu Fujino

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 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 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

We prove the abundance theorem for semi log canonical surfaces in positive characteristic.

Algebraic Geometry · Mathematics 2015-10-20 Hiromu Tanaka

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 Angehrn-Siu type effective base point freeness and point separation for log canonical pairs.

Algebraic Geometry · Mathematics 2009-11-13 Osamu Fujino

We show Fujita's spectrum conjecture for $\epsilon$-log canonical pairs and Fujita's log spectrum conjecture for log canonical pairs. Then, we generalize the pseudo-effective threshold of a single divisor to multiple divisors and establish…

Algebraic Geometry · Mathematics 2017-06-21 Jingjun Han , Zhan Li

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 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

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 a conjecture due to V.V. Shokurov on the boundedness of $\epsilon$-log canonical complements on surfaces. As an application we give a new proof to the boundedness of weak log Fano surfaces.

Algebraic Geometry · Mathematics 2007-05-23 Caucher Birkar

In this paper, we show the abundance theorem for log canonical surfaces over fields of positive characteristic.

Algebraic Geometry · Mathematics 2019-02-15 Hiromu Tanaka

We prove that the pull-back of a quasi-log scheme by a smooth quasi-projective morphism has a natural quasi-log structure. We treat an application to log Fano pairs. This paper also contains a proof of the simple connectedness of log Fano…

Algebraic Geometry · Mathematics 2016-06-21 Osamu Fujino

In this paper, we show how to prove the basepoint-freeness for linear systems on irregular varieties inductively. For instance, we prove that Fujita's conjecture holds for irregular varieties of dimension $\mathnormal{n}$ with a nef…

Algebraic Geometry · Mathematics 2025-09-17 Houari Benammar Ammar

This treats the base-point-freeness of the adjoint bundles on normal surfaces with a boundary. This is an extension of the non-relative version of the theorem of Ein-Lazarsfeld-Masek and the theorem of Kawachi-Masek.

alg-geom · Mathematics 2008-02-03 Takeshi Kawachi
‹ Prev 1 2 3 10 Next ›