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Related papers: Fano threefolds and K3 surfaces

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There exist exactly 166 4-dimensional reflexive polytopes such that the corresponding 4-dimensional Gorenstein toric Fano varieties have at worst terminal singularities in codimension 3 and their anticanonical divisor is divisible by 2. For…

Algebraic Geometry · Mathematics 2017-08-23 Victor Batyrev , Maximilian Kreuzer

For a general K3 surface of genus g = 2,3,...,10, we prove that the intermediate jacobians of the family of prime Fano threefolds of genus g containing S as a hyperplane section, form generically an algebraic completely integrable system.

Algebraic Geometry · Mathematics 2007-05-23 Atanas Iliev , Laurent Manivel

We show that if an ample line bundle L on a nonsingular toric 3-fold satisfies h^0(L+2K)=0, then L is normally generated. As an application, we show that the anti-canonical divisor on a nonsingular toric Fano 4-fold is normally generated.

Algebraic Geometry · Mathematics 2013-10-25 Shoetsu Ogata

We use classification of non-symplectic automorphisms of K3 surfaces to obtain a partial classification of log del Pezzo surfaces of index three. We can classify those with "Multiple Smooth Divisor Property", whose definition we will give.…

Algebraic Geometry · Mathematics 2012-03-27 Hisanori Ohashi , Shingo Taki

In this paper we address Fano manifolds X with a locally unsplit dominating family of rational curves of anticanonical degree equal to the dimension of X. We first observe that their Picard number is at most 3, and then we provide a…

Algebraic Geometry · Mathematics 2015-01-12 Cinzia Casagrande , Stéphane Druel

We prove that the Fano variety of lines of a generic cubic fourfold containing a plane is isomorphic to a moduli space of twisted stable complexes on a K3 surface. On the other hand, we show that the Fano varieties are always birational to…

Algebraic Geometry · Mathematics 2011-12-26 Emanuele Macri , Paolo Stellari

We find a relation between a cubic hypersurface $Y$ and its Fano variety of lines $F(Y)$ in the Grothendieck ring of varieties. We prove that if the class of an affine line is not a zero-divisor in the Grothendieck ring of varieties, then…

Algebraic Geometry · Mathematics 2014-06-27 Sergey Galkin , Evgeny Shinder

We study Fano fourfolds of K3 type with a conic bundle structure. We construct direct geometrical links between these fourfolds and hyperK\"ahler varieties. As a result we describe families of nodal surfaces that can be seen as…

Given $\epsilon>0$, we show that over an algebraically closed field of characteristic $p>5$, the anticanonical volume of a Fano threefold $X$ (with arbitrary singularities) whose anticanonical divisor has Seshadri constant…

Algebraic Geometry · Mathematics 2020-08-05 Ziquan Zhuang

We consider a semistable degeneration of K3 surfaces, equipped with an effective divisor that defines a polarisation of degree two on a general fibre. We show that the map to the relative log canonical model of the degeneration maps every…

Algebraic Geometry · Mathematics 2013-12-09 Alan Thompson

We show that a Hilbert scheme of conics on a Fano fourfold double cover of $\mathbb{P}^2\times\mathbb{P}^2$ ramified along a divisor of bidegree $(2,2)$ admits a $\mathbb{P}^1$-fibration with base being a hyper-K\"{a}hler fourfold. We…

Algebraic Geometry · Mathematics 2017-08-15 Atanas Iliev , Grzegorz Kapustka , Michał Kapustka , Kristian Ranestad

Some of the 95 families of weighted K3 hypersurfaces have been known to have the isometric lattice polarizations. It is shown that weighted K3 hypersurfaces in such families are to one-to-one correspond by explicitly constructing the…

Algebraic Geometry · Mathematics 2010-09-14 Masanori Kobayashi , Makiko Mase

Let X be a K3 surface and H a primitive polarization of degree H^2=2a^2, a>1. The moduli space of sheaves over X with the isotropic Mukai vector (a,H,a) is again a K3 surface Y which is endowed by a natural nef element h with h^2=2. We give…

Algebraic Geometry · Mathematics 2007-05-23 Carlo Madonna , Viacheslav V. Nikulin

We analyse the local structure of the K-moduli space of Fano varieties at a toric singular K-polystable Fano 3-fold, which deforms to smooth Fano 3-folds with anticanonical volume 28 and Picard rank 4. In particular, by constructing an…

Algebraic Geometry · Mathematics 2024-10-04 Liana Heuberger , Andrea Petracci

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

This article settles the question of existence of smooth weak Fano threefolds of Picard number two with small anti-canonical map and previously classified numerical invariants obtained by blowing up certain curves on smooth Fano threefolds…

Algebraic Geometry · Mathematics 2015-02-10 Maxim Arap , Joseph Cutrone , Nicholas Marshburn

In this paper, we check that Fano schemes of lines on certain rational cubic fourfolds are birational to Hilbert schemes of two points on K3 surfaces.

Algebraic Geometry · Mathematics 2018-05-15 Genki Ouchi

Let $X$ be a Fano manifold of Picard number one. We establish a lower bound for the second Chern class of $X$ in terms of its index and degree. As an application, if $Y$ is a $n$-dimensional Fano manifold with $-K_Y=(n-3)H$ for some ample…

Algebraic Geometry · Mathematics 2018-05-29 Jie Liu

In this paper, we deal with the linear Weingarten factorable surfaces in the isotropic 3-space I^{3} satisfying the relation aK+bH=c, where K is the relative curvature and H the isotropic mean curvature, a,b,cR. We obtain a complete…

Differential Geometry · Mathematics 2017-06-05 Muhittin Evren Aydin , Alper Osman Ogrenmis

In this article we prove some strong vanishing theorems on K3 surfaces. As an aplication of them, we obtain higher syzygy results for K3 surfaces and Fano varieties.

alg-geom · Mathematics 2008-02-03 F. J. Gallego , B. P. Purnaprajna