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Related papers: Birational geometry of singular Fano varieties

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We prove divisorial canonicity of Fano double hypersurfaces of general position.

Algebraic Geometry · Mathematics 2009-11-13 Aleksandr Pukhlikov

We establish birational superrigidity for a large class of singular projective Fano hypersurfaces of index one. In the special case of isolated singularities, our result applies for instance to: (1) hypersurfaces with semi-homogeneous…

Algebraic Geometry · Mathematics 2016-04-07 Tommaso de Fernex

We prove birational superrigidity of Fano double hypersurfaces of index one with quadratic and multi-quadratic singularities, satisfying certain regularity conditions, and give an effective explicit lower bound for the codimension of the…

Algebraic Geometry · Mathematics 2018-12-31 Thomas Eckl , Aleksandr Pukhlikov

We complete the study of birational geometry of Fano fiber spaces $\pi\colon V\to {\mathbb P}^1$, the fiber of which is a Fano double hypersurface of index 1. For each family of these varieties we either prove birational rigidity or produce…

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

We survey some results on the nonrationality and birational rigidity of certain hypersurfaces of Fano type. The focus is on hypersurfaces of Fano index one, but hypersurfaces of higher index are also discussed.

Algebraic Geometry · Mathematics 2014-01-08 Tommaso de Fernex

It is proved that a general Fano hypersurface of index 1 (in the projective space) with isolated singularities of general position is birationally rigid. Therefore it cannot be fibered into uniruled varieties of a smaller dimension by a…

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

We develop the quadratic technique of proving birational rigidity of Fano-Mori fibre spaces over a higher-dimensional base. As an application, we prove birational rigidity of generic fibrations into Fano double spaces of dimension…

Algebraic Geometry · Mathematics 2017-12-15 Aleksandr V. Pukhlikov

We prove birational superrigidity of every hypersurface of degree N in P^N with singular locus of dimension s, under the assumption that N is at least 2s+8 and it has only quadratic singularities of rank at least N-s. Combined with the…

Algebraic Geometry · Mathematics 2016-06-23 Fumiaki Suzuki

We prove birational superrigidity of Fano cyclic covers of index 1 over hypersurfaces in the projective space.

Algebraic Geometry · Mathematics 2007-05-23 Aleksandr V. Pukhlikov

We prove the birational rigidity of Fano complete intersections of index 1 with a singular point of high multiplicity, which can be close to the degree of the variety. In particular, the groups of birational and biregular automorphisms of…

Algebraic Geometry · Mathematics 2017-11-07 Aleksandr V. Pukhlikov

We introduce an inductive argument for proving birational superrigidity and K-stability of singular Fano complete intersections of index one, using the same types of information from lower dimensions. In particular, we prove that a…

Algebraic Geometry · Mathematics 2021-08-30 Yuchen Liu , Ziquan Zhuang

We prove birational superrigidity of generic Fano fiber spaces $V/{\mathbb P}^1$, the fibers of which are Fano complete intersections of index 1 and dimension $M$ in ${\mathbb P}^{M+k}$, provided that $M\geq 2k+1$. The proof combines the…

Algebraic Geometry · Mathematics 2007-05-23 Aleksandr V. Pukhlikov

We prove that a general Fano fibration $\pi\colon V\to {\mathbb P}^1$, the fiber of which is a double Fano hypersurface of index 1, is birationally superrigid provided it is sufficiently twisted over the base. In particular, on $V$ there…

Algebraic Geometry · Mathematics 2007-05-23 Aleksandr V. Pukhlikov

We study birational geometry of Fano varieties, realized as double covers $\sigma\colon V\to {\mathbb P}^M$, $M\geq 5$, branched over generic hypersurfaces $W=W_{2(M-1)}$ of degree $2(M-1)$. We prove that the only structures of a rationally…

Algebraic Geometry · Mathematics 2009-05-22 Aleksandr Pukhlikov

In this paper, we give some results on the birational geometry of varieties of Fano type and boundedness problems in positive characteristic, including a result ensuring that boundedness is invariant under normalizations, a canonical bundle…

Algebraic Geometry · Mathematics 2025-03-10 Xintong Jiang

It is shown that hypersurfaces of degree $M$ in ${\mathbb P}^M$, $M\geqslant 5$, with at most quadratic singularities of rank at least 3, satisfying certain conditions of general position, are birationally superrigid Fano varieties and the…

Algebraic Geometry · Mathematics 2023-12-29 Aleksandr V. Pukhlikov

We continue to study birational geometry of Fano fibrations $\pi\colon V\to {\mathbb P}^1$ the fibers of which are Fano double hypersurfaces of index 1. For a majority of families of this type, which do not satisfy the condition of…

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

We find new lower bounds on the torsion orders of very general Fano hypersurfaces over (uncountable) fields of arbitrary characteristic. Our results imply that unirational parametrizations of most Fano hypersurfaces need to have enormously…

Algebraic Geometry · Mathematics 2021-03-03 Stefan Schreieder

We prove that every non-trivial structure of a rationally connected fibre space (and so every structure of a Mori-Fano fibre space) on a general (in the sense of Zariski topology) hypersurface of degree $M$ in the $(M+1)$-dimensional…

Algebraic Geometry · Mathematics 2013-11-14 Aleksandr Pukhlikov

We show that the degrees of rational endomorphisms of very general complex Fano and Calabi-Yau hypersurfaces satisfy certain congruence conditions by specializing to characteristic p. As a corollary we show that very general n-dimensional…

Algebraic Geometry · Mathematics 2022-05-20 Nathan Chen , David Stapleton
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