English
Related papers

Related papers: Fano threefolds with sections in $\Omega_V^1(1)$

200 papers

Let X be a smooth, complex Fano 4-fold, and rho(X) its Picard number. If X contains a prime divisor D with rho(X)-rho(D)>2, then either X is a product of del Pezzo surfaces, or rho(X)=5 or 6. In this setting, we completely classify the case…

Algebraic Geometry · Mathematics 2020-07-23 Cinzia Casagrande , Eleonora A. Romano

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…

Algebraic Geometry · Mathematics 2024-08-15 Nikolay Konovalov

Let X be a Fano manifold of pseudoindex i_X whose Picard number is at least two and let R be an extremal ray of X with exceptional locus Exc(R). We prove an inequality which bounds the length of R in terms of i_X and of the dimension of…

Algebraic Geometry · Mathematics 2007-05-23 Marco Andreatta , Gianluca Occhetta

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

Let $X$ be a complex smooth Fano variety of dimension $n$. In this paper, we give a classification of such $X$ when the pseudoindex is equal to $\dfrac{\dim X+1}{2}$ and the Picard number greater than one.

Algebraic Geometry · Mathematics 2024-09-23 Kiwamu Watanabe

We show that a non-toric $\mathbb{Q}$-factorial terminal Fano threefold of Picard rank $1$ and Fano index $13$ is a weighted hypersurface of degree $12$ in $\mathbb{P}(3,4,5,6,7)$.

Algebraic Geometry · Mathematics 2026-01-22 Yuri Prokhorov

We construct $S$-linear semiorthogonal decompositions of derived categories of smooth Fano threefold fibrations $X/S$ with relative Picard rank $1$ and rational geometric fibers and discuss how the structure of components of these…

Algebraic Geometry · Mathematics 2022-10-03 Alexander Kuznetsov

Let $X$ be a projective Fano manifold of Picard number one, different from the projective space. There is a folklore conjecture that any non-constant endomorphism of $X$ is an isomorphism. In the first half of this article, we will prove…

Algebraic Geometry · Mathematics 2023-08-08 Sarbeswar Pal

In this paper, we study the explicit geometry of threefolds, in particular, Fano varieties. We find an explicitly computable positive integer $N$, such that all but a bounded family of Fano threefolds have $N$-complements. This result has…

Algebraic Geometry · Mathematics 2023-11-14 Caucher Birkar , Jihao Liu

We construct several new families of Fano varieties of K3 type. We give a geometrical explanation of the K3 structure and we link some of them to projective families of irreducible holomorphic symplectic manifolds.

Algebraic Geometry · Mathematics 2019-04-12 Enrico Fatighenti , Giovanni Mongardi

We construct first examples of Fano varieties with torsion in their third cohomology group. The examples are constructed as double covers of linear sections of rank loci of symmetric matrices, and can be seen as higher-dimensional analogues…

Algebraic Geometry · Mathematics 2023-11-17 John Christian Ottem , Jørgen Vold Rennemo

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 classify the non-toric, $\mathbb Q$-factorial, Gorenstein, log terminal Fano threefolds of Picard number one that admit an effective action of a two-dimensional algebraic torus.

Algebraic Geometry · Mathematics 2022-11-17 Andreas Bäuerle , Jürgen Hausen

Fano surfaces parametrize the lines of smooth cubic threefolds. In this paper, we study their quotients by some of their automorphism sub-groups. We obtain in that way some interesting surfaces of general type.

Algebraic Geometry · Mathematics 2012-02-10 Xavier Roulleau

We classify rank two vector bundles on a Fano threefold of Picard rank one whose projectivizations are weak Fano. We also prove the existence of examples for each case of the classification result. Our classification includes detailed…

Algebraic Geometry · Mathematics 2025-05-07 Takeru Fukuoka , Wahei Hara , Daizo Ishikawa

We classify birationally rigid orbifold Fano 3-folds of index one defined by $5 \times 5$ Pfaffians. We give a sharp criterion for birational rigidity of these families based on the type of singularities that the varieties admit. Various…

Algebraic Geometry · Mathematics 2022-07-22 Hamid Abban , Takuzo Okada

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 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 prove that a quasi-smooth Fano threefold hypersurface is birationally rigid if and only if it has Fano index one.

Algebraic Geometry · Mathematics 2020-07-29 Hamid Ahmadinezhad , Ivan Cheltsov , Jihun Park

We prove that the Fano variety of lines of a cuspidal cyclic cubic fourfold is a symplectic variety with transversal A2-singularities and we study the properties of the nonsymplectic order three automorphism induced by the covering…

Algebraic Geometry · Mathematics 2023-03-28 Samuel Boissiere , Tobias Heckel , Alessandra Sarti
‹ Prev 1 3 4 5 6 7 10 Next ›