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Related papers: Pluricanonical maps for threefolds of general type

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We prove that the canonical volume $K^3\geq {1/30}$ for all projective 3-folds of general type with $\chi(\mathcal{O})\leq 0$. This bound is sharp.

Algebraic Geometry · Mathematics 2008-06-27 Jungkai A. Chen , Meng Chen

In this paper, we prove the abundance conjecture for threefolds over a perfect field $k$ of characteristic $p > 3$ in the case of numerical dimension equals to $2$. More precisely, we prove that if $(X,B)$ be a projective lc threefold pair…

Algebraic Geometry · Mathematics 2026-04-20 Zheng Xu

Let $X$ be a smooth complex projective variety such that the Albanese map of $X$ is generically finite onto its image. Here we study the so-called eventual $m$-paracanonical map of $X$ (when $m=1$ we also assume $\chi(K_X)>0$). We show that…

Algebraic Geometry · Mathematics 2023-12-29 Miguel Ángel Barja , Rita Pardini , Lidia Stoppino

We study threefolds of general type constructed as $\mathbb{Z}_2^s$-covers of weighted projective spaces with a particular focus on their invariants, deformation theory, and the behavior of the $m$-canonical map. For the invariants, we…

Algebraic Geometry · Mathematics 2026-05-08 Patricio Gallardo , Jayan Mukherjee

We study lower bounds for the self-intersection of the canonical divisor of "canonical varieties" (i.e. varieties whose canonical linear system gives a birational map). We give some improvements for the known results in the case of surfaces…

Algebraic Geometry · Mathematics 2007-05-23 Miguel A. Barja

We construct a class of positive linear maps on matrix algebras. We find conditions when these maps are atomic, decomposable and completely positive. We obtain a large class of atomic positive linear maps. As applications in quantum…

Operator Algebras · Mathematics 2017-04-25 Xin Li , Wei Wu

A rational map between certain specific threefolds is given in an explicit manner.

Algebraic Geometry · Mathematics 2007-05-23 Kenichiro Kimura

In this paper, we classify irregular threefolds with numerically trivial canonical divisors in positive characteristic. For such a variety, if its Albanese dimension is not maximal, then the Albanese morphism will induce a fibration which…

Algebraic Geometry · Mathematics 2026-01-28 Jingshan Chen , Chongning Wang , Lei Zhang

This is a modest attempt to study, in a systematic manner, the structure of low dimensional varieties in positive characteristics using $p$-adic invariants. The main objects of interest in this paper are surfaces and threefolds. It is known…

Algebraic Geometry · Mathematics 2020-12-07 Kirti Joshi

We investigate the combinatorial analogues, in the context of normal surfaces, of taut and transversely measured (codimension 1) foliations of 3-manifolds. We establish that the existence of certain combinatorial structures, a priori weaker…

Geometric Topology · Mathematics 2007-05-23 Danny Calegari

This article discusses the recent transcendental techniques used in the proofs of the following three conjectures. (1)~The plurigenera of a compact projective algebraic manifold are invariant under holomorphic deformation. (2)~There exists…

Complex Variables · Mathematics 2007-05-23 Yum-Tong Siu

This paper shows that the Seifert volume of each closed non-trivial graph manifold is virtually positive. As a consequence, for each closed orientable prime 3-manifold $N$, the set of mapping degrees $\c{D}(M,N)$ is finite for any…

Geometric Topology · Mathematics 2014-02-26 Pierre Derbez , Shicheng Wang

In this paper, we show that if $X$ is a smooth variety of general type of dimension $m \geq 3$ for which the canonical map induces a triple cover onto $Y$, where $Y$ is a projective bundle over $\mathbf P^1$ or onto a projective space or…

Algebraic Geometry · Mathematics 2015-11-24 Francisco Javier Gallego , Miguel Gonzalez , Bangere P. Purnaprajna

We prove that small deformations of a projective variety of general type are also projective varieties of general type, with the same plurigenera. Version 2: small changes in first half. Improved version of the second half is now a separate…

Algebraic Geometry · Mathematics 2022-02-09 János Kollár

In this paper, by using the trace map of Frobenius, we consider problems on extending sections for positive characteristic threefolds.

Algebraic Geometry · Mathematics 2015-02-06 Hiromu Tanaka

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

Surfaces of general type with positive second Segre number are known to have big cotangent bundle. We give a new criterion ensuring that a surface of general type with canonical singularities has a minimal resolution with big cotangent…

Algebraic Geometry · Mathematics 2015-01-14 Xavier Roulleau , Erwan Rousseau

We investigate equivariant birational geometry of rational surfaces and threefolds from the perspective of derived categories.

Algebraic Geometry · Mathematics 2023-11-28 Christian Böhning , Hans-Christian Graf von Bothmer , Yuri Tschinkel

We give an up-to-date overview of the known results on the bicanonical map of surfaces of general type with $p_g=0$ and $K^2\ge 2$.

Algebraic Geometry · Mathematics 2007-05-23 Margarida Mendes Lopes , Rita Pardini

One develops {\em ab initio} the theory of rational/birational maps over reduced, but not necessarily irreducible, projective varieties in arbitrary characteristic. A numerical invariant of a rational map is introduced, called the Jacobian…

Commutative Algebra · Mathematics 2012-03-28 A. V. Dória , S. H. Hassanzadeh , A. Simis
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