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Related papers: Derived category of V_{12} Fano threefolds

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In this note we study Fano threefolds with noncyclic torsion in the divisor class group. Since they can all be obtained as quotients of Fano threefolds, we get also all examples that can be obtained as quotients of low codimension Fanos in…

Algebraic Geometry · Mathematics 2007-06-14 Jorge Caravantes

The present paper deals with lines contained in a smooth complex cubic threefold. It is well-known that the set of lines of the second type on a cubic threefold is a curve on its Fano surface. Here we give a description of the singularities…

Algebraic Geometry · Mathematics 2022-02-03 Gloire Grace Bockondas , Samuel Boissiere

Consider a family of Fano varieties $\pi: X \longrightarrow B\ni o$ over a curve germ with a smooth total space $X$. Assume that the generic fiber is smooth and the special fiber $F=\pi^{-1}(o)$ has simple normal crossings. Then $F$ is…

Algebraic Geometry · Mathematics 2019-09-23 Konstantin Loginov

We give an explicit construction of prime Fano threefolds of genus 12 with a $G_m$-action, describe their isomorphism classes and automorphism groups.

Algebraic Geometry · Mathematics 2023-06-22 Alexander Kuznetsov , Yuri Prokhorov

We show that, for a Q-Fano threefold X of Fano index 2, the inequality dim |-1/2K_X| <= 4 holds with a single well understood family of varieties having dim |-1/2K_X| = 4.

Algebraic Geometry · Mathematics 2016-06-29 Yuri Prokhorov , Miles Reid

This paper is devoted to the study of holomorphic distributions of dimension and codimension one on smooth weighted projective complete intersection Fano manifolds threedimensional, with Picard number equal to one. We study the relations…

Algebraic Geometry · Mathematics 2020-01-31 Alana Cavalcante , Mauricio Corrêa , Simone Marchesi

We prove that the derived category of a smooth complete intersection variety is equivalent to a full subcategory of the derived category of a smooth projective Fano variety. This enables us to define some new invariants of smooth projective…

Algebraic Geometry · Mathematics 2015-04-30 Young-Hoon Kiem , In-Kyun Kim , Hwayoung Lee , Kyoung-Seog Lee

We produce a list of 64 families of Fano fourfolds of K3 type, extracted from our database of at least 634 Fano fourfolds constructed as zero loci of general global sections of completely reducible homogeneous vector bundles on products of…

Algebraic Geometry · Mathematics 2025-05-23 Marcello Bernardara , Enrico Fatighenti , Laurent Manivel , Fabio Tanturri

We study the K-moduli space of products of Fano varieties in relation to the product of K-moduli spaces of the product components. We show that there exists a well-defined morphism from the product of K-moduli stacks of Fano varieties to…

Algebraic Geometry · Mathematics 2024-05-15 Thedoros S. Papazachariou

A threefold isogenous to a product of curves $X$ is a quotient of a product of three compact Riemann surfaces of genus at least two by the free action of a finite group. In this paper we study these threefolds under the assumption that the…

Algebraic Geometry · Mathematics 2017-03-09 Davide Frapporti , Christian Gleissner

Let X be the blow-up of a smooth projective 4-fold Y along a smooth curve C and let E be the exceptional divisor. Assume that X is a Fano manifold and has an elementary extremal contraction $\phi: X \to Z$ of (3,1)-type such that E is…

Algebraic Geometry · Mathematics 2007-10-10 Toru Tsukioka

Let $\Cal E$ be a very ample vector bundle of rank two on a smooth complex projective threefold $X$. An inequality about the third Segre class of $\Cal E$ is provided when $K_X+\det \Cal E$ is nef but not big, and when a suitable positive…

Algebraic Geometry · Mathematics 2007-05-23 Hidetoshi Maeda , Andrew Sommese

A Fano-Enriques threefold is a three-dimensional non-Gorenstein Fano variety of index 1 with at most canonical singularities. We study the birational geometry of Fano-Enriques threefolds with terminal cyclic quotient singularities. We…

Algebraic Geometry · Mathematics 2023-01-19 Arman Sarikyan

In this paper, we provide examples of Sarkisov links of type II between complex projective Fano threefolds $X$ with $\rho(X) = 1$. To show examples of these links, we study smooth weak Fano threefolds with extremal rays of type $E$. We…

Algebraic Geometry · Mathematics 2014-01-07 Joseph W. Cutrone , Nicholas A. Marshburn

We introduce a new technique, based on Gaussian maps, to study the possibility, for a given surface, to lie on a threefold as a very ample divisor with given normal bundle. We give several applications, among which one to surfaces of…

Algebraic Geometry · Mathematics 2016-08-16 A. L. Knutsen , A. F. Lopez , R. Muñoz

A criterion for a functor between derived categories of coherent sheaves to be full and faithful is given. A semiorthogonal decomposition for the derived category of coherent sheaves on the intersection of two even dimensional quadrics is…

alg-geom · Mathematics 2008-02-03 A. Bondal , D. Orlov

We study the symplectic resolution of the Fano variety of lines on some singular cyclic cubic fourfolds, i.e. cubic fourfolds arising as cyclic 3:1 cover of $\mathbb{P}^4$ branched along a cubic threefold. In particular we are interested in…

Algebraic Geometry · Mathematics 2023-12-27 Samuel Boissière , Paola Comparin , Lucas Li Bassi

A normal projective variety X is called Fano if a multiple of the anticanonical Weil divisor, -K_X, is an ample Cartier divisor, the index of a Fano variety is the number i(X):=sup{t: -K_X= tH, for some ample Cartier divisor H}. Mukai…

alg-geom · Mathematics 2008-02-03 Massimiliano Mella

We consider Fano threefolds $V$ with canonical Gorenstein singularities. A sharp bound $-K_V^3\le 72$ of the degree is proved.

Algebraic Geometry · Mathematics 2025-11-26 Yuri G. Prokhorov

This paper classifies rank two vector bundles on a del Pezzo threefold $X$ of degree five whose projectivizations are weak Fano. This classification is then used to determine properties of the moduli spaces of such vector bundles on $X$,…

Algebraic Geometry · Mathematics 2025-05-08 Takeru Fukuoka , Wahei Hara , Daizo Ishikawa