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Related papers: Fano threefolds in positive characteristic III

200 papers

We construct examples of Fano manifolds, which are defined over a field of positive characteristic, but not over $\com$.

Algebraic Geometry · Mathematics 2017-06-20 Ilya Karzhemanov

In this paper, we investigate Fano manifolds whose Chern characters satisfy some positivity conditions. We prove that such manifolds admit long chains of higher order minimal families of rational curves and are covered by higher rational…

Algebraic Geometry · Mathematics 2024-07-19 Taku Suzuki

We continue the classification of terminal Fano threefolds with an effective two-torus action. In earlier work we settled the Q-factorial case with Picard number one. Here we treat the larger class of varieties that do not admit any…

Algebraic Geometry · Mathematics 2018-03-13 Michele Nicolussi

An inductive approach to classifying toric Fano varieties is given. As an application of this technique, we present a classification of the toric Fano threefolds with at worst canonical singularities. Up to isomorphism, there are 674,688…

Algebraic Geometry · Mathematics 2019-08-15 Alexander M. Kasprzyk

Using a construction due to C. Casagrande and further developed by the author, we prove that the Picard number of a non-smooth Fano 3-fold with isolated factorial canonical singularities, is at most 6.

Algebraic Geometry · Mathematics 2013-01-14 Gloria Della Noce

We prove that all smooth Fano threefolds in the families 2.1, 2.2, 2.3, 2.4, 2.6 and 2.7 are K-stable, and we also prove that smooth Fano threefolds in the family 2.5 that satisfy one very explicit generality condition are K-stable.

Algebraic Geometry · Mathematics 2024-01-17 Ivan Cheltsov , Elena Denisova , Kento Fujita

We classify some special classes of non-rational Fano threefolds with terminal singularities. In particular, all such hyperelliptic and trigonal varieties are found.

Algebraic Geometry · Mathematics 2019-07-15 Yuri Prokhorov

We construct an explicit semistable degeneration of a Fano eightfold of index three and deduce its Hodge numbers, in particular we show that it has Picard rank one. The Fano variety is of K3 type and it is defined as a connected component…

Algebraic Geometry · Mathematics 2025-12-17 Vanja Zuliani

It was Fano who first classified Enriques-Fano threefolds. However his arguments appear to contain several gaps. In this paper, we will verify some of his assertions through the use of modern techniques.

Algebraic Geometry · Mathematics 2021-07-12 Vincenzo Martello

In characteristic $0$, the Campana-Peternell conjecture claims that the only smooth Fano variety with nef tangent bundle should be homogeneous. In this paper, we study the positive characteristic version of the Campana-Peternell conjecture.…

Algebraic Geometry · Mathematics 2022-11-01 Yuta Takahashi , Kiwamu Watanabe

For $n\geq 4$, let $X$ be a complex smooth Fano $n$-fold whose minimal anticanonical degree of non-free rational curves on $X$ is at least $n-2$. We classify extremal contractions of such varieties. As an application, we obtain a…

Algebraic Geometry · Mathematics 2024-06-04 Kiwamu Watanabe

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…

Algebraic Geometry · Mathematics 2025-07-17 Joseph Malbon

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…

Algebraic Geometry · Mathematics 2025-05-12 Tatsuro Kawakami , Hiromu Tanaka

We study Fano 3-folds with Fano index 2: that is, 3-folds X with rank Pic(X) = 1, Q-factorial terminal singularities and -K_X = 2A for an ample Weil divisor A. We give a first classification of all possible Hilbert series of such polarised…

Algebraic Geometry · Mathematics 2007-05-23 Gavin Brown , Kaori Suzuki

We classify the terminal Fano threefolds of Picard number one that come with an effective action of a two-torus. Our approach applies also to higher dimensions and generalizes the correspondence between toric Fano varieties and lattice…

Algebraic Geometry · Mathematics 2025-07-08 Benjamin Bechtold , Elaine Huggenberger , Juergen Hausen , Michele Nicolussi

We classify Fano fivefolds of index two which are blow-ups of smooth manifolds along a smooth center.

Algebraic Geometry · Mathematics 2017-09-29 Elena Chierici , Gianluca Occhetta

We classify mildly singular Fano varieties $X$ such that $\mathrm{Nef}(X)=\mathrm{Psef}(X)$ and that the Picard number of $X$ is equal to the dimension of $X$ minus $1$.

Algebraic Geometry · Mathematics 2018-04-13 Wenhao Ou

In this paper, we classify Fano fourfolds whose the second exterior power of tangent bundles are numerically effective with Picard number greater than one.

Algebraic Geometry · Mathematics 2014-01-14 Kazunori Yasutake

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…

Algebraic Geometry · Mathematics 2014-06-25 Yuri Prokhorov , Mikhail Zaidenberg

For any positive integer $k$ and any integer $n$ large enough, we construct a Fano variety $X$ with Picard number $k$ and dimension $n$ such that $((-K_X)^n)^{1/n}$ grows like $n^k/(\log n)^{k-1}$.

Algebraic Geometry · Mathematics 2007-05-23 Olivier Debarre