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Related papers: Birational geometry of singular Fano varieties

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Let X be a Fano manifold of dimension n and index n-3. Kawamata proved the non vanishing of the global sections of the fundamental divisor in the case n=4. Moreover he proved that if Y is a general element of the fundamental system then Y…

Algebraic Geometry · Mathematics 2012-01-12 Enrica Floris

We prove that a smooth Fano hypersurface $V=V_M\subset{\Bbb P}^M$, $M\geq 6$, is birationally superrigid. In particular, it cannot be fibered into uniruled varieties by a non-trivial rational map and each birational map onto a minimal Fano…

Algebraic Geometry · Mathematics 2015-06-26 Aleksandr V. Pukhlikov

In this paper we study the geometry of mildly singular Fano varieties on which there is an effective prime divisor of Picard number one. Afterwards, we address the case of toric varieties. Finally, we treat the lifting of extremal…

Algebraic Geometry · Mathematics 2017-09-07 Pedro Montero

We give some rationality constructions for Fano threefolds with canonical Gorenstein singularities.

Algebraic Geometry · Mathematics 2010-05-04 Yuri G. Prokhorov

In this paper we describe the birational geometry of Fano double spaces $V\stackrel{\sigma}{\to}{\mathbb P}^{M+1}$ of index 2 and dimension $\geqslant 8$ with at mostquadratic singularities of rank $\geqslant 8$, satisfying certain…

Algebraic Geometry · Mathematics 2019-12-11 Aleksandr V. Pukhlikov

We classify three-dimensional Fano varieties with canonical Gorenstein singularities of degree bigger than 64.

Algebraic Geometry · Mathematics 2015-05-13 Ilya Karzhemanov

Under a hypothesis on $k$, $d$ and $n$ that is almost the best possible, we prove that for every smooth degree $d$ hypersurface in $P^n$, the $k$-plane sections dominate the moduli space of degree $d$ hypersurface in $P^k$. Using this we…

Algebraic Geometry · Mathematics 2007-05-23 Jason Michael Starr

This paper explores the Fano variety of lines in hypersurfaces, particularly focusing on those with mild singularities. Our first result explores the irreducibility of the variety $\Sigma$ of lines passing through a singular point $y$ on a…

Algebraic Geometry · Mathematics 2025-03-12 Jiayi Hu , Fengyang Wang , Xinlang Zhu

We prove birational superrigidity of direct products $V=F_1\times...\times F_K$ of primitive Fano varieties of the following two types: either $F_i\subset{\mathbb P}^M$ is a general hypersurface of degree $M$, $M\geq 6$, or…

Algebraic Geometry · Mathematics 2015-06-26 Aleksandr V. Pukhlikov

We prove that a general Fano hypersurface in a projective space over an algebraically closed field of arbitrary characteristic is separably rationally connected.

Algebraic Geometry · Mathematics 2011-11-15 Yi Zhu

We study degree of irrationality of quasismooth anticanonically embedded weighted Fano 3-fold hypersurfaces that have terminal singularities.

Algebraic Geometry · Mathematics 2022-10-27 Ivan Cheltsov , Jihun Park

We show that any Fano fivefold with canonical Gorenstein singularities has an effective anticanonical divisor. Moreover,if a general element of the anticanonical system is reduced, then it has canonical singularities. We also prove…

Algebraic Geometry · Mathematics 2020-02-10 Andreas Höring , Robert Śmiech

Iterating the procedure of making a double cover over a given variety, we construct large families of smooth higher-dimensional Fano varieties of index 1. These varieties can be realized as complete intersections in various weighted…

Algebraic Geometry · Mathematics 2015-06-26 Aleksandr V. Pukhlikov

We classify birational maps into elliptic fibrations of a general quasismooth hypersurface in $\mathbb{P}(1,a_{1},a_{2},a_{3},a_{4})$ of degree $\sum_{i=1}^{4}a_{i}$ that has terminal singularities.

Algebraic Geometry · Mathematics 2007-05-23 Ivan Cheltsov

We provide enumerative formulas for the degrees of varieties parameterizing hypersurfaces and complete intersections which contain pro-jective subspaces and conics. Besides, we find all cases where the Fano scheme of the general complete…

Algebraic Geometry · Mathematics 2019-04-18 Ciro Ciliberto , M Zaidenberg

We show that the set of Fano varieties (with arbitrary singularities) whose anticanonical divisors have large Seshadri constants satisfies certain weak and birational boundedness. We also classify singular Fano varieties of dimension $n$…

Algebraic Geometry · Mathematics 2021-02-22 Ziquan Zhuang

The purpose of the present paper is to generalize Sakai's work on anticanonical models of rational surfaces to varieties of Fano type. We first prove a characterization of Fano type varieties using the singularities of anticanonical models.…

Algebraic Geometry · Mathematics 2014-12-30 Sung Rak Choi , DongSeon Hwang , Jinhyung Park

In this paper we prove the birational superrigidity of Fano-Mori fibre spaces $\pi\colon V\to S$, every fibre of which is a complete intersection of type $d_1\cdot d_2$ in the projective space ${\mathbb P}^{d_1+d_2}$, satisfying certain…

Algebraic Geometry · Mathematics 2021-07-14 Aleksandr V. Pukhlikov

In this paper we show that a general element of $|-K_X|$ on a four-dimensional Fano manifold has at most terminal singularities. We then determine an explicit local expression of these singular points.

Algebraic Geometry · Mathematics 2015-05-12 Liana Heuberger

We classify Fano 3-folds with canonical Gorenstein singularities whose anticanonical linear system has no base points but does not give an embedding, and we classify anticanonically embedded Fano 3-folds with canonical Gorenstein…

Algebraic Geometry · Mathematics 2007-05-23 Ivan Cheltsov , Constantin Shramov , Victor Przyjalkowski