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Related papers: Abundance conjecture

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We present a short proof of the abundance theorem in the case of numerical Kodaira dimension 0 proved by Nakayama and its log generalizaton.

Algebraic Geometry · Mathematics 2010-05-18 Yujiro Kawamata

We prove that for a compact K\"ahler threefold with canonical singularities and vanishing first Chern class, the projective fibres are dense in the semiuniversal deformation space. This implies that every K\"ahler threefold of Kodaira…

Algebraic Geometry · Mathematics 2020-11-05 Patrick Graf

We express the Kodaira-Iitaka dimension and the multiplicity of graded linear series in terms of the intersection theory of the plurisubharmonic envelope associated with the linear series, and obtain two refined versions of these formulas…

Complex Variables · Mathematics 2026-03-24 Siarhei Finski

In this short note we prove the Iitaka C_nm conjecture for algebraic fiber spaces over surfaces

Algebraic Geometry · Mathematics 2017-07-31 Junyan Cao

In this note we study properties of partially ample line bundles on simplicial projective toric varieties. We prove that the cone of q-ample line bundles is a union of rational polyhedral cones, and calculate these cones in examples. We…

Algebraic Geometry · Mathematics 2014-09-29 Nathan Broomhead , John Christian Ottem , Artie Prendergast-Smith

In this paper, we prove the abundance theorem for numerically trivial canonical divisors on strongly $F$-regular varieties, assuming that the geometric generic fibers of the Albanese morphisms are strongly $F$-regular.

Algebraic Geometry · Mathematics 2022-04-19 Sho Ejiri

We present a simplified proof for a recent theorem by Junyan Cao and Mihai Paun, confirming a special case of Iitaka's conjecture: if $f \colon X\to Y$ is an algebraic fiber space, and if the Albanese mapping of $Y$ is generically finite…

Algebraic Geometry · Mathematics 2017-05-11 Christopher Hacon , Mihnea Popa , Christian Schnell

This is the first of a series of papers, in which we study the plurigenera, the Kodaira dimension and more generally the Iitaka dimension on compact almost complex manifolds. Based on the Hodge theory on almost complex manifolds, we…

Differential Geometry · Mathematics 2020-04-28 Haojie Chen , Weiyi Zhang

Let Y be a projective non-singular curve of genus g, X a projective manifold, both defined over the field of complex numbers, and let f:X ---> Y be a surjective morphism with general fibre F. If the Kodaira dimension of X is non-negative,…

Algebraic Geometry · Mathematics 2007-05-23 Eckart Viehweg , Kang Zuo

Fujino gave a proof in [Fuj03] for the semi-ampleness of the moduli part in the canonical bundle formula in the case when the general fibers are K3 surfaces or Abelian varieties. We show a similar statement when the general fibers are…

Algebraic Geometry · Mathematics 2024-05-10 Hyunsuk Kim

We study very basic slc-trivial fibrations. We show that restricting on any lc center of a very basic slc-trivial fibration, its moduli part is numerically trivial if and only if it is $\mathbb Q$-linearly trivial. We then prove that…

Algebraic Geometry · Mathematics 2020-10-23 Haidong Liu

We show, using [14], that a smooth projective fibration f : X $\rightarrow$ Y between connected complex quasi-projective manifolds satisfies the equality $\kappa$(X) = $\kappa$(X y) + $\kappa$(Y) of Logarithmic Kodaira dimensions if its…

Algebraic Geometry · Mathematics 2023-03-09 Frederic Bruno Campana

We study the complex-analytic geometry of semi-positive holomorphic line bundles on compact K\"ahler manifolds. In one of our main results, for a $\mathbb{Q}$-effective line bundle satisfying a natural torsion-type assumption, we show the…

Complex Variables · Mathematics 2026-01-23 Takayuki Koike

We shall show how to decompose, by functorial and canonical fibrations, arbitrary $n$-dimensional complex projective {Although the geometric results apply to compact K\" ahler manifolds without change, we consider here for simplicity this…

Algebraic Geometry · Mathematics 2010-01-22 Frederic Campana

Let $f:X\to Y$ be an algebraic fiber space with general fiber $F$. If $Y$ is of maximal Albanese dimension, we show that $\kappa (X)\geq \kappa (Y)+\kappa (F)$.

Algebraic Geometry · Mathematics 2015-05-19 Jungkai Alfred Chen , Christopher D. Hacon

We show that an everywhere regular foliation $\mathcal F$ with compact canonically polarized leaves on a quasi-projective manifold $X$ has isotrivial family of leaves when the orbifold base of this family is special. By a recent work of…

Algebraic Geometry · Mathematics 2017-09-22 Ekaterina Amerik , Frédéric Campana

We show that the Kahler-Ricci flow on an algebraic manifold of positive Kodaira dimension and semi-ample canonical line bundle converges to a unique canonical metric on its canonical model. It is also shown that there exists a canonical…

Differential Geometry · Mathematics 2008-02-20 Jian Song , Gang Tian

Given a (meromorphic) fibration $f:X\to Y$ where $X$ and $Y$ are compact complex manifolds of dimensions $n$ and $m$, we define $L_f$ to be the invertible subsheaf of the sheaf of holomorphic $m$-forms of $X$ given by the saturation of…

Algebraic Geometry · Mathematics 2007-05-23 Steven S. Y. Lu

The notion of Kodaira dimension has recently been extended to general almost complex manifolds. In this paper we focus on the Kodaira dimension of almost K\"ahler manifolds, providing an explicit computation for a family of almost K\"ahler…

Differential Geometry · Mathematics 2019-09-04 Andrea Cattaneo , Antonella Nannicini , Adriano Tomassini

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