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Related papers: Terminal Fano threefolds and their smoothings

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We show that mixed-characteristic and equi-characteristic small deformations of 3-dimensional canonical (resp. terminal) singularities with perfect residue field of characteristic $p>5$ are canonical (resp. terminal). We discuss…

Algebraic Geometry · Mathematics 2024-03-08 Fabio Bernasconi , Iacopo Brivio , Stefano Filipazzi

We study toric G-solid Fano threefolds that have at most terminal singularities, where G is an algebraic subgroup of the normalizer of a maximal torus in their automorphism groups.

Algebraic Geometry · Mathematics 2023-02-03 Ivan Cheltsov , Adrien Dubouloz , Takashi Kishimoto

We prove the following main result: Let X be a Fano 3-fold with terminal Q-factorial singularities and X does not have a small extremal ray and a face of Kodaira dimension 1 or 2 for Mori polyhedron of X. Then the Picard number \rho (X) <…

alg-geom · Mathematics 2008-02-03 Viacheslav V. Nikulin

We study Gorenstein almost Fano threefolds X with canonical singularities and pseudoindex > 1. We show that the maximal Picard number of X is 10 in general, 3 if X is Fano, and 8 if X is toric. Moreover, we characterize the boundary cases.…

Algebraic Geometry · Mathematics 2007-05-23 C. Casagrande , P. Jahnke , I. Radloff

In this article, we prove that any Q-Calabi-Yau 3-fold with only ordinary terminal singularities and any Q-Fano 3-fold of Fano index 1 with only terminal singularities have Q-smoothings.

Algebraic Geometry · Mathematics 2007-05-23 Tatsuhiro Minagawa

Using a construction due to C. Casagrande and further developed by the author, we prove that the Picard number of a non-smooth Fano 3-fold with isolated factorial canonical singularities, is at most 6.

Algebraic Geometry · Mathematics 2013-01-14 Gloria Della Noce

We study the deformation theory of a Q-Fano 3-fold with only terminal singularities. First, we show that the Kuranishi space of a Q-Fano 3-fold is smooth. Second, we show that every Q-Fano 3-fold with only "ordinary" terminal singularities…

Algebraic Geometry · Mathematics 2014-10-30 Taro Sano

We classify toric Fano threefolds having at worst terminal singularities such that a rank of a $G$-invariant part of a class group equals one, where $G$ is a group acting on the variety by automorphisms.

Algebraic Geometry · Mathematics 2022-09-05 Arman Sarikyan

We classify smooth Fano threefolds with infinite automorphism groups.

Algebraic Geometry · Mathematics 2021-06-11 Ivan Cheltsov , Victor Przyjalkowski , Constantin Shramov

We prove that all smooth Fano threefolds in the families 2.1, 2.2, 2.3, 2.4, 2.6 and 2.7 are K-stable, and we also prove that smooth Fano threefolds in the family 2.5 that satisfy one very explicit generality condition are K-stable.

Algebraic Geometry · Mathematics 2024-01-17 Ivan Cheltsov , Elena Denisova , Kento Fujita

We prove that all smooth Fano threefolds with Picard rank 2 and degree 28 are K-polystable, except for some explicit cases which we describe. We also give a classification of the normal bundle of a rational normal quartic curve in a smooth…

Algebraic Geometry · Mathematics 2025-07-17 Joseph Malbon

We classify Fano threefolds with only terminal singularities whose canonical class is Cartier and divisible by 2, and satisfying an additional assumption that the $G$-invariant part of the Weil divisor class group is of rank 1 with respect…

Algebraic Geometry · Mathematics 2013-08-06 Yuri Prokhorov

We consider Fano threefolds $V$ with canonical Gorenstein singularities. A sharp bound $-K_V^3\le 72$ of the degree is proved.

Algebraic Geometry · Mathematics 2025-11-26 Yuri G. Prokhorov

We give new proofs of the K-polystability of two smooth Fano threefolds. One of them is a~smooth divisor in $\mathbb{P}^1\times\mathbb{P}^1\times\mathbb{P}^2$ of degree $(1,1,1)$, which is unique up to isomorphism. Another one is the~blow…

Algebraic Geometry · Mathematics 2021-07-13 Ivan Cheltsov , Hendrik Süß

This paper is devoted to the study of holomorphic distributions of dimension and codimension one on smooth weighted projective complete intersection Fano manifolds threedimensional, with Picard number equal to one. We study the relations…

Algebraic Geometry · Mathematics 2020-01-31 Alana Cavalcante , Mauricio Corrêa , Simone Marchesi

We obtain upper bounds on the number of singular points of factorial terminal Fano threefolds.

Algebraic Geometry · Mathematics 2017-08-02 Yu. Prokhorov

For fixed degree $d\leq 12$, we study the Hilbert scheme of degree $d$ smooth Fano threefolds in their anticanonical embeddings. We use this to classify all possible degenerations of these varieties to toric Fano varieties with at most…

Algebraic Geometry · Mathematics 2019-11-26 Jan Arthur Christophersen , Nathan Owen Ilten

We study Fano threefolds with Picard number one equipped with a holomorphic section in $\Omega_V^1(1)$.

Algebraic Geometry · Mathematics 2007-05-23 Priska Jahnke , Ivo Radloff

This article settles the question of existence of smooth weak Fano threefolds of Picard number two with small anti-canonical map and previously classified numerical invariants obtained by blowing up certain curves on smooth Fano threefolds…

Algebraic Geometry · Mathematics 2015-02-10 Maxim Arap , Joseph Cutrone , Nicholas Marshburn

We classify smooth Fano manifolds X with the Picard number $\rho_X \geq 3$ such that there exists an extremal ray which has a birational contraction that maps a divisor to a point.

Algebraic Geometry · Mathematics 2012-12-21 Kento Fujita