English
Related papers

Related papers: Fano Hypersurfaces in Positive Characteristic

200 papers

In this paper, we show that general Fano complete intersections over an algebraically closed field of arbitrary characteristics are separably rationally connected. Our proof also implies that general log Fano complete intersections with…

Algebraic Geometry · Mathematics 2015-07-03 Qile Chen , Yi Zhu

We prove that a projective surface of globally $F$-regular type defined over a field of characteristic zero is of Fano type.

Algebraic Geometry · Mathematics 2015-06-17 Shinnosuke Okawa

A very general hypersurface of dimension $n$ and degree $d$ in complex projective space is rational if $d \leq 2$, but is expected to be irrational for all $n, d \geq 3$. Hypersurfaces in weighted projective space with degree small relative…

Algebraic Geometry · Mathematics 2024-11-20 Louis Esser

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

This article proves hypersurfaces of degree d in projective n-space are "rationally simply-connected" if $d^2 \leq n$. In a forthcoming paper, de Jong and I prove a slightly weaker result when $d^2 \leq n+1$.

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

In this paper, we show that projective globally $F$-regular threefolds, defined over an algebraically closed field of characteristic $p\geq 11$, are rationally chain connected.

Algebraic Geometry · Mathematics 2015-05-19 Yoshinori Gongyo , Zhiyuan Li , Zsolt Patakfalvi , Karl Schwede , Hiromu Tanaka , Hong R. Zong

We use birational geometry to show that the existence of rational points on proper rationally connected varieties over fields of characteristic $0$ is a consequence of the existence of rational points on terminal Fano varieties. We discuss…

Algebraic Geometry · Mathematics 2021-08-06 Marta Pieropan

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

We prove that a fibration X \to \Bbb P_1, the general fiber of which is a smooth Fano threefold, is rationally connected. The proof is based on a generalization of Tsen's classical theorem: a fibration X/C over a curve the general fiber of…

Algebraic Geometry · Mathematics 2015-06-26 Frederic Campana , Thomas Peternell , Aleksandr Pukhlikov

In this short note we prove that in many cases the failure of a variety to be separably rationally connected is caused by the instability of the tangent sheaf (if there are no other obvious reasons). A simple application of the results…

Algebraic Geometry · Mathematics 2014-07-30 Zhiyu Tian

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 study rational curves on general Fano hypersurfaces in projective space, mostly by degenerating the hypersurface along with its ambient projective space to reducible varieties. We prove results on existence of low-degree rational curves…

Algebraic Geometry · Mathematics 2020-03-11 Ziv Ran

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 get sharp degree bound for generic smoothness and connectedness of the space of conics in low degree complete intersections which generalizes the old work about Fano scheme of lines on Hypersurfaces.

Algebraic Geometry · Mathematics 2013-07-25 Hong R. Zong

Let X be a smooth hypersurface of degree d in P^n over an algebraically closed field of characteristic p. We show that X must be separably rationally connected and must contain a free line if either p is at least d or if p is at least d-1…

Algebraic Geometry · Mathematics 2025-12-19 Roya Beheshti , Shibashis Mukhopadhyay , Eric Riedl

We prove divisorial canonicity of Fano hypersurfaces and double spaces of general position with elementary singularities.

Algebraic Geometry · Mathematics 2008-07-25 Aleksandr Pukhlikov

We prove that any smooth rational projective surface over the field of complex numbers has an open covering consisting of 3 subsets isomorphic to affine planes.

Algebraic Geometry · Mathematics 2022-03-23 Jorge Caravantes , J. Rafael Sendra , David Sevilla , Carlos Villarino

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 give the first evidence for a conjecture that a general, index-one, Fano hypersurface is not unirational: (i) a general point of the hypersurface is contained in no rational surface ruled, roughly, by low-degree rational curves, and (ii)…

Algebraic Geometry · Mathematics 2007-05-23 Roya Beheshti , Jason Michael Starr

We show that the Fargues--Fontaine curve associated to an algebraically closed field of characteristic p is geometrically simply connected; that is, its base extension from Q_p to any complete algebraically closed overfield admits no…

Number Theory · Mathematics 2021-01-20 Kiran S. Kedlaya
‹ Prev 1 2 3 10 Next ›