English
Related papers

Related papers: A note on the abundance conjecture

200 papers

We prove the Nonvanishing conjecture for uniruled projective log canonical pairs of dimension $n$, assuming the Nonvanishing conjecture for smooth projective varieties in dimension $n-1$. We also show that the existence of good minimal…

Algebraic Geometry · Mathematics 2022-05-23 Vladimir Lazić , Fanjun Meng

We prove that the abundance conjecture holds on a variety $X$ with mild singularities if $X$ has many reflexive differential forms with coefficients in pluricanonical bundles, assuming the Minimal Model Program in lower dimensions. This…

Algebraic Geometry · Mathematics 2025-08-22 Vladimir Lazić , Thomas Peternell

We show that the non-vanishing conjecture implies the abundance conjecture when $\nu\leq 1$. We also prove the abundance conjecture in dimension $\leq 5$ when $\kappa\geq 0$ and $\nu\leq 1$ unconditionally.

Algebraic Geometry · Mathematics 2025-08-01 Jihao Liu , Zheng Xu

In our previous work, we introduced the Generalised Nonvanishing Conjecture, which generalises several central conjectures in algebraic geometry. In this paper, we derive some surprising nonvanishing results for pluricanonical bundles which…

Algebraic Geometry · Mathematics 2020-04-01 Vladimir Lazić , Thomas Peternell

We treat two different topics on the log minimal model program, especially for four-dimensional log canonical pairs. (a) Finite generation of the log canonical ring in dimension four. (b) Abundance theorem for irregular fourfolds. We obtain…

Algebraic Geometry · Mathematics 2015-01-14 Osamu Fujino

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

We add further notions to Lehmann's list of numerical analogues to the Kodaira dimension of pseudo-effective divisors on smooth complex projective varieties, and show new relations between them. Then we use these notions and relations to…

Algebraic Geometry · Mathematics 2016-01-05 Thomas Eckl

We prove that the existence of log minimal models in dimension $d$ essentially implies the LMMP with scaling in dimension $d$. As a consequence we prove that a weak nonvanishing conjecture in dimension $d$ implies the minimal model…

Algebraic Geometry · Mathematics 2009-07-27 Caucher Birkar

Under the assumption of the minimal model theory for projective klt pairs of dimension $n$, we establish the minimal model theory for lc pairs $(X/Z,\Delta)$ such that the log canonical divisor is relatively log abundant and its restriction…

Algebraic Geometry · Mathematics 2019-08-29 Kenta Hashizume , Zhengyu Hu

We prove the finiteness of $B$-representations of generalised log canonical pairs. As a consequence, we prove that, the (relative) abundance for a generalised semi-log canonical pair is implied by the abundance for its normalisation.…

Algebraic Geometry · Mathematics 2021-03-23 Zhengyu Hu

Let $\overline{\mathrm{Mov}}^k(X)$ be the closure of the cone $\mathrm{Mov}^k(X)$ generated by classes of effective divisors on a projective variety $X$ with stable base locus of codimension at least $k+1$. We propose a generalized version…

Algebraic Geometry · Mathematics 2024-05-24 Gilberto Bini , Maria Chiara Brambilla , Claudio Fontanari , Elisa Postinghel

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

We show the abundance theorem for arithmetic klt threefold pairs whose closed point have residue characteristic greater than five. As a consequence, we give a sufficient condition for the asymptotic invariance of plurigenera for certain…

Algebraic Geometry · Mathematics 2022-11-24 Fabio Bernasconi , Iacopo Brivio , Liam Stigant

In this paper, we show that the minimal model theory does not hold in characteristic two. More precisely, we construct counter-examples to the relative abundance conjecture.

Algebraic Geometry · Mathematics 2013-12-17 Hiromu Tanaka

We show that a weak version of the canonical bundle formula holds for fibrations of relative dimension one. We provide various applications thereof, for instance, using the recent result of Xu and Zhang, we prove the log non-vanishing…

Algebraic Geometry · Mathematics 2018-04-11 Jakub Witaszek

We use the canonical bundle formula for parabolic fibrations to give an inductive approach to the generalized abundance conjecture using nef reduction. In particular, we observe that generalized abundance holds for a klt pair $(X,B)$ if the…

Algebraic Geometry · Mathematics 2022-09-12 Priyankur Chaudhuri

We use reduction maps to study the minimal model program. Our main result is that the existence of a good minimal model for a klt pair $(X,\Delta)$ can be detected on the base of the $(K_{X}+\Delta)$-trivial reduction map. Thus we show that…

Algebraic Geometry · Mathematics 2019-02-20 Yoshinori Gongyo , Brian Lehmann

We prove the abundance theorem for log canonical $n$-folds such that the boundary divisor is big assuming the abundance conjecture for log canonical $(n-1)$-folds. We also discuss the log minimal model program for log canonical $4$-folds.

Algebraic Geometry · Mathematics 2015-11-04 Kenta Hashizume

In this article we prove two cases of the abundance conjecture for $3$-folds in characteristic $p>5$: $(i)$ $(X, \Delta)$ is KLT and $\kappa(X, K_X+\Delta)=1$, and $(ii)$ $(X, 0)$ is KLT, $K_X\equiv 0$ and $X$ is not uniruled.

Algebraic Geometry · Mathematics 2018-09-03 Omprokash Das , Joe Waldron

We reduce the Abundance Conjecture in dimension 4 to the following numerical statement: if the canonical divisor K is nef and has maximal nef dimension, then K is big. From this point of view, we ``classify'' in dimension 2 nef divisors…

Algebraic Geometry · Mathematics 2007-05-23 Florin Ambro
‹ Prev 1 2 3 10 Next ›