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Related papers: On the rationality of certain Fano threefolds

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We classify some special classes of non-rational Fano threefolds with terminal singularities. In particular, all such hyperelliptic and trigonal varieties are found.

Algebraic Geometry · Mathematics 2019-07-15 Yuri Prokhorov

We prove rationality criteria over algebraically non-closed fields of characteristic $0$ for five out of six types of geometrically rational Fano threefolds of Picard number $1$ and geometric Picard number bigger than $1$. For the last type…

Algebraic Geometry · Mathematics 2022-08-04 Alexander Kuznetsov , Yuri Prokhorov

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

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

We classify nonrational Fano threefolds $X$ with terminal Gorenstein singularities such that $\mathrm{\rk}\, \mathrm{\Pic}(X)=1$, $(-K_X)^3\ge 8$, and $\mathrm{\rk}\, \mathrm{\Cl}(X)\le 2$.

Algebraic Geometry · Mathematics 2022-05-18 Yuri Prokhorov

We prove that for $n \leq 4$ and $p > 5$, quasi--Gorenstein $F$--pure and $\mathbb{Q}_p$--rational $n$--fold singularities are canonical. This is analogous to the usual fact that rational Gorenstein singularities are canonical. The proof is…

Algebraic Geometry · Mathematics 2025-06-19 Jefferson Baudin , Zsolt Patakfalvi , Linus Rösler , Maciej Zdanowicz

We give necessary and sufficient conditions for unirationality and rationality of Fano threefolds of geometric Picard rank-1 over an arbitrary field of zero characteristic.

Algebraic Geometry · Mathematics 2021-04-29 Alexander Kuznetsov , Yuri Prokhorov

We prove that $\mathbb{Q}$-Fano threefolds of Fano index $\ge 8$ are rational.

Algebraic Geometry · Mathematics 2019-03-19 Yuri Prokhorov

We study the connectedness of the real locus of smooth geometrically rational Fano threefolds and prove a sufficient criterion of $\mathbb{R}$-rationality.

Algebraic Geometry · Mathematics 2025-07-08 Andrea Fanelli , Frédéric Mangolte

We study unirationality and rationality of Fano threefolds of degree 18 over nonclosed fields.

Algebraic Geometry · Mathematics 2019-10-31 Brendan Hassett , Yuri Tschinkel

We determine the rationality of very general quasismooth Fano 3-fold weighted hypersurfaces completely and determine the stable rationality of them except for cubic 3-folds. More precisely we prove that (i) very general Fano 3-fold weighted…

Algebraic Geometry · Mathematics 2017-09-25 Takuzo Okada

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

We study the spaces of rational curves on Fano threefolds with Gorenstein terminal singularities. We generalize the results regarding Geometric Manin's Conjecture for smooth Fano threefolds, including the classification of subvarieties with…

Algebraic Geometry · Mathematics 2025-05-23 Fumiya Okamura

We prove that a prime Fano threefold of genus 8 over an algebraically closed field of positive characteristic is isomorphic to a linear section of the Grassmannian variety Gr(2, 6). As applications, it is shown that a prime Fano threefold…

Algebraic Geometry · Mathematics 2026-04-13 Akihiro Kanemitsu , Hiromu Tanaka

We prove the $W\mathcal{O}$-rationality of klt threefolds and the rational chain connectedness of klt Fano threefolds over a perfect field of characteristic $p>5$. As a consequence, any klt Fano threefold over a finite field has a rational…

Algebraic Geometry · Mathematics 2016-12-01 Yoshinori Gongyo , Yusuke Nakamura , Hiromu Tanaka

We discuss birational properties of Mukai varieties, i.e., of higher-dimensional analogues of prime Fano threefolds of genus $g \in \{7,8,9,10\}$ over an arbitrary field $\mathsf{k}$ of zero characteristic. In the case of dimension $n \ge…

Algebraic Geometry · Mathematics 2020-03-25 Alexander Kuznetsov , Yuri Prokhorov

For $X$ a smooth cubic threefold we study the Pl\"ucker embedding of the Fano surface of lines $S$ of $X$. We prove that if $X$ is general then the minimal gonality of a covering family of curves of $S$ is four and that this happens for a…

Algebraic Geometry · Mathematics 2018-05-04 Frank Gounelas , Alexis Kouvidakis

This paper studies the birational geometry of terminal Gorenstein Fano 3-folds. If Y is not Q-factorial, in most cases, it is possible to describe explicitly the divisor class group Cl Y by running a Minimal Model Program (MMP) on X, a…

Algebraic Geometry · Mathematics 2009-08-04 Anne-Sophie Kaloghiros

We investigate the rationality problem for $\mathbf{Q}$-Fano threefolds of Fano index $\ge 2$.

Algebraic Geometry · Mathematics 2026-01-22 Yuri Prokhorov

We show that polarized endomorphisms of rationally connected threefolds with at worst terminal singularities are equivariantly built up from those on Q-Fano threefolds, Gorenstein log del Pezzo surfaces and P^1. Similar results are obtained…

Algebraic Geometry · Mathematics 2019-02-20 De-Qi Zhang

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

Algebraic Geometry · Mathematics 2015-05-13 Ilya Karzhemanov
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