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Related papers: Terminal Fano threefolds and their smoothings

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

Algebraic Geometry · Mathematics 2015-05-13 Ilya Karzhemanov

We classify smooth Fano threefolds that admit degenerations to toric Fano threefolds with ordinary double points.

Algebraic Geometry · Mathematics 2018-09-11 Sergey Galkin

We compute global log canonical thresholds of some smooth Fano threefolds.

Algebraic Geometry · Mathematics 2009-02-08 Ivan Cheltsov , Constantin Shramov

We study the deformation theory of a Fano variety X with normal crossing singularities of dimension at most three. We obtain a formula for the sheaf T^1(X) of first order deformations of X in a suitable log resolution of X and its singular…

Algebraic Geometry · Mathematics 2009-07-22 Nikolaos Tziolas

We classify primitive Fano threefolds in positive characteristic whose Picard numbers are at least two. We also classify Fano theefolds of Picard rank two.

Algebraic Geometry · Mathematics 2025-07-24 Masaya Asai , Hiromu Tanaka

We study the Picard variety of the Fano surface of nodal and mildly cuspidal cubic threefolds in arbitrary characteristic by relating divisors on the Fano surface to divisors on the symmetric product of a curve of genus 4.

Algebraic Geometry · Mathematics 2010-10-12 Gerard van der Geer , Alexis Kouvidakis

We provide a complete classification of Fano threefolds X having canonical Gorenstein singularities and the anticanonical degree (-KX)^3 equal 64.

Algebraic Geometry · Mathematics 2014-11-20 Ilya Karzhemanov

We study Fano threefolds with~terminal singularities admitting a "minimal" action of a finite group. We prove that under certain additional assumptions such a variety does not contain planes. We also obtain an upper bounds of the number of…

Algebraic Geometry · Mathematics 2019-08-14 Yuri Prokhorov

In this paper we prove that any smooth prime Fano threefold, different from the Mukai-Umemura threefold, contains a 1-dimensional family of intersecting lines. Combined with a result of the second author (see J. Algebr. Geom. 8:2 (1999),…

Algebraic Geometry · Mathematics 2007-05-23 Atanas Iliev , Carmen Schuhmann

We classify the possible images of the action of the group of automorphisms of a smooth Fano threefold on its Picard group. We also study the first group cohomology of the Picard group for families of smooth Fano threefolds.

Algebraic Geometry · Mathematics 2025-11-18 Shreya Sharma

We prove the conjectural Bogomolov-Gieseker type inequality for tilt slope stable objects on each Fano threefold X of Picard number one. Based on the previous works on Bridgeland stability conditions, this induces an open subset of…

Algebraic Geometry · Mathematics 2016-02-15 Chunyi Li

Let $X$ be a smooth Fano threefold over an algebraically closed field of positive characteristic. Assume that $|-K_X|$ is very ample and each of the index and the Picard number is equal to one. We prove that $3 \leq g \leq 12$ and $g \neq…

Algebraic Geometry · Mathematics 2024-10-03 Hiromu Tanaka

We give some bounds on the anticanonical degrees of Fano varieties with Picard number 1 and mild singularities, extending results of Koll\'ar et al. from the early 90's and improving them even in the smooth case. The proof is based on a…

Algebraic Geometry · Mathematics 2007-05-23 Ziv Ran , Herb Clemens

In this paper we study smooth, complex Fano 4-folds X with large Picard number rho(X), with techniques from birational geometry. Our main result is that if X is isomorphic in codimension one to the blow-up of a smooth projective 4-fold Y at…

Algebraic Geometry · Mathematics 2017-04-06 Cinzia Casagrande

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 coregularity of smooth Fano threefolds. We prove that for 100 out of 105 families of smooth Fano threefolds, a general member in the family has coregularity 0; moreover, for 92 families out of these 100, any member in the…

Algebraic Geometry · Mathematics 2024-10-01 Artem Avilov , Konstantin Loginov , Victor Przyjalkowski

We show that the Picard rank is constant in families of Fano varieties (in arbitrary characteristic) and we moreover investigate the constancy of the index.

Algebraic Geometry · Mathematics 2017-04-12 Frank Gounelas , Ariyan Javanpeykar

Let $X$ be a smooth threefold over an algebraically closed field of positive characteristic. We prove that an arbitrary flop of $X$ is smooth. To this end, we study Gorenstein curves of genus one and two-dimensional elliptic singularities…

Algebraic Geometry · Mathematics 2025-10-22 Hiromu Tanaka

We present some applications of the deformation theory of toric Fano varieties to K-(semi/poly)stability of Fano varieties. First, we present two examples of K-polystable toric Fano 3-fold with obstructed deformations. In one case, the…

Algebraic Geometry · Mathematics 2021-09-02 Anne-Sophie Kaloghiros , Andrea Petracci