中文
相关论文

相关论文: Rationality of Fano threefolds over non-closed fie…

200 篇论文

We study links between algebraic cycles on threefolds and finite-dimensionality of their motives with coefficients in Q. We decompose the motive of a non-singular projective threefold X with representable algebraic part of CH_0(X) into…

代数几何 · 数学 2015-04-06 S. Gorchinskiy , V. Guletskii

We show that the optimal upper bound for the anticanonical degrees of non-Gorenstein $\mathbb{Q}$-factorial canonical Fano threefolds with Picard number one is 200/3.

代数几何 · 数学 2026-01-21 Minyou Li

We prove that in a family of projective threefolds defined over an algebraically closed field, the locus of rational fibers is a countable union of closed subsets of the locus of separably rationally connected fibers. When the ground field…

代数几何 · 数学 2012-05-16 Tommaso de Fernex , Davide Fusi

This paper studies the defect of terminal Gorenstein Fano 3 folds. I determine a bound on the defect of terminal Gorenstein Fano 3-folds of Picard rank 1 that do not contain a plane. I give a general bound for quartic 3-folds and indicate…

代数几何 · 数学 2009-08-24 Anne-Sophie Kaloghiros

In this paper the notion of rational simple connectedness for the quintic Fano threefold $V_5\subset \mathbb{P}^6$ is studied and unirationality of the moduli spaces $\overline{M}_{0,0}^{\text{bir}}(V_5,d)$, with $d \ge 1$, is proved. Many…

代数几何 · 数学 2019-01-23 Andrea Fanelli , Laurent Gruson , Nicolas Perrin

We prove that all smooth Fano threefolds with Picard rank 2 and degree 28 are K-polystable, except for some explicit cases which we describe. We also give a classification of the normal bundle of a rational normal quartic curve in a smooth…

代数几何 · 数学 2025-07-17 Joseph Malbon

We show that complex Fano hypersurfaces can have arbitrarily large degrees of irrationality. More precisely, if we fix a Fano index e, then the degree of irrationality of a very general complex Fano hypersurface of index e and dimension n…

代数几何 · 数学 2021-11-11 Nathan Chen , David Stapleton

We study (smooth, complex) Fano 4-folds X having a rational contraction of fiber type, that is, a rational map X-->Y that factors as a sequence of flips followed by a contraction of fiber type. The existence of such a map is equivalent to…

代数几何 · 数学 2020-06-24 Cinzia Casagrande

In this paper we address Fano manifolds with positive higher Chern characters. They are expected to enjoy stronger versions of several of the nice properties of Fano manifolds. For instance, they should be covered by higher dimensional…

We obtain a sufficient condition for a Fano threefold with terminal singularities to have a conic bundle structure.

代数几何 · 数学 2022-02-02 Yuri Prokhorov

We study rationality properties of real singular cubic threefolds.

代数几何 · 数学 2024-11-22 Ivan Cheltsov , Yuri Tschinkel , Zhijia Zhang

We prove K-stability of smooth Fano 3-folds of Picard rank 3 and degree 20 that satisfy very explicit generality condition.

代数几何 · 数学 2024-03-15 Elena Denisova

In this paper, we prove a conjecture by T. Suzuki, which says if a smooth Fano manifold satisfies some positivity condition on its Chern character, then it can be covered by rational $N$-folds. We prove this conjecture by using purely…

代数几何 · 数学 2018-05-31 Takahiro Nagaoka

We show that the degrees of rational endomorphisms of very general complex Fano and Calabi-Yau hypersurfaces satisfy certain congruence conditions by specializing to characteristic p. As a corollary we show that very general n-dimensional…

代数几何 · 数学 2022-05-20 Nathan Chen , David Stapleton

We explore connections between existence of $\Bbbk$-rational points for Fano varieties defined over $\Bbbk$, a subfield of $\mathbb{C}$, and existence of K\"ahler-Einstein metrics on their geometric models. First, we show that geometric…

代数几何 · 数学 2024-11-04 Hamid Abban , Ivan Cheltsov , Takashi Kishimoto , Frederic Mangolte

We construct 4 di erent families of smooth Fano fourfolds with Picard rank 1, which contain cylinders, i.e., Zariski open subsets of the form Z x A1, where Z is a quasiprojective variety. The affi ne cones over such a fourfold admit eff…

代数几何 · 数学 2014-06-25 Yuri Prokhorov , Mikhail Zaidenberg

We prove K-stability of smooth Fano 3-folds of Picard rank 3 and degree 22 that satisfy very explicit generality condition.

代数几何 · 数学 2024-01-08 Ivan Cheltsov

We prove the Shafarevich conjecture for Fano threefolds of Picard rank 1, index 1 and degree 4.

代数几何 · 数学 2022-07-13 Philipp Licht

In our series of papers, we prove that smooth Fano threefolds in positive characteristic lift to the ring of Witt vectors. Moreover, we show that they satisfy Akizuki-Nakano vanishing, $E_1$-degeneration of the Hodge to de Rham spectral…

代数几何 · 数学 2025-03-14 Tatsuro Kawakami , Hiromu Tanaka

Let $\mathcal{X}$ be a smooth Fano threefold over the complex numbers of Picard rank $1$ with finite automorphism group. We give numerical restrictions on the order of the automorphism group $\mathrm{Aut}(\mathcal{X})$ provided the genus…

代数几何 · 数学 2024-08-15 Nikolay Konovalov