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Related papers: Terminal Fano threefolds and their smoothings

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Let $X$, $Y$ be Fano threefolds of Picard number one and such that the ample generators of Picard groups are very ample. Let $X$ be of index one and $Y$ be of index two. It is shown that the only morphisms from $X$ to $Y$ are double…

Algebraic Geometry · Mathematics 2007-05-23 Ekaterina Amerik

We give examples of Fano varieties $X$ with Picard number 1, which have terminal singularities and admit endomorphisms with degree larger than 1.

Algebraic Geometry · Mathematics 2009-01-14 János Kollár , Chenyang Xu

We study degree of irrationality of quasismooth anticanonically embedded weighted Fano 3-fold hypersurfaces that have terminal singularities.

Algebraic Geometry · Mathematics 2022-10-27 Ivan Cheltsov , Jihun Park

We prove the $K$-polystability of all smooth complex Fano threefolds admitting an effective action of $\text{SL}_2$ but not of a 2-torus or 3-torus. In particular, the existence of K\"{a}hler-Einstein metrics on varieties in the families…

Algebraic Geometry · Mathematics 2022-01-12 Jack Rogers

Applying Geometric Invariant Theory (GIT), we study the stability of foliations of degree 3 on P^2 with a unique singular point of multiplicity 1, 2, or 3 and Milnor number 13. In particular, we characterize those foliations for…

Algebraic Geometry · Mathematics 2023-04-11 Abel Castorena , P. Rubí Pantaleón-Mondragón , Juan Vásquez Aquino

We prove that a weak Fano manifold has unobstructed deformations. For a general variety, we investigate conditions under which a variety is necessarily obstructed.

Algebraic Geometry · Mathematics 2013-05-23 Taro Sano

We show that certain Galois covers of K-semistable Fano varieties are K-stable. We use this to give some new examples of Fano manifolds admitting K\"ahler-Einstein metrics, including hypersurfaces, double solids and threefolds.

Algebraic Geometry · Mathematics 2018-05-16 Ruadhaí Dervan

We consider resolution of singularities for $1$-foliations on varieties of dimension at most three in positive characteristic. We prove that such singularities can be completely resolved if we allow tame regular Deligne--Mumford stacks as…

Algebraic Geometry · Mathematics 2025-08-12 Quentin Posva

By identifying K-polystable limits in 4 specific deformations families of smooth Fano 3-folds, we complete the classification of one-dimensional components in the K-moduli space of smoothable Fano 3-folds.

We continue the classification of terminal Fano threefolds with an effective two-torus action. In earlier work we settled the Q-factorial case with Picard number one. Here we treat the larger class of varieties that do not admit any…

Algebraic Geometry · Mathematics 2018-03-13 Michele Nicolussi

In this note, we study K-stability of smooth Fano threefolds that can be obtained by blowing up the three-dimensional projective space along a smooth elliptic curve of degree five.

Algebraic Geometry · Mathematics 2024-07-09 Ivan Cheltsov , Piotr Pokora

By using the classification of Fano 3-folds we prove: Let $X$ be Fano 3-fold. Assume that the tangent bundle $T_X$ of $X$ is not stable (i.e. semi-stable or unstable). Then $b_2\geq 2$ and a relative tangent sheaf $T_{X/Y}$ of a contraction…

alg-geom · Mathematics 2008-02-03 Andreas Steffens

We classify the smooth Fano 4-folds of Picard number two that have a general hypersurface Cox ring.

Algebraic Geometry · Mathematics 2025-07-01 Juergen Hausen , Antonio Laface , Christian Mauz

Let $X$ and $Y$ be two analytic canonical Gorenstein orbifolds. A resolution of singularities $Y\to X$ is called an Euler resolution if $Y$ and $X$ have the same orbifold Euler number. If $Y$ is only terminal rather than smooth, it is…

alg-geom · Mathematics 2008-02-03 Alexander V. Sardo Infirri

We show the existence of Bridgeland stability conditions on all Fano threefolds, by proving a modified version of a conjecture by Bayer, Toda, and the second author. The key technical ingredient is a strong Bogomolov inequality, proved…

Algebraic Geometry · Mathematics 2023-06-22 Marcello Bernardara , Emanuele Macrì , Benjamin Schmidt , Xiaolei Zhao

The existence is proved of two new families of locally Cohen-Macaulay sextic threefolds in $\mathbb{P}^5$, which are not quadratically normal. These threefolds arise naturally in the realm of first order congruences of lines as focal loci…

Algebraic Geometry · Mathematics 2014-06-13 Pietro De Poi , Emilia Mezzetti

In this paper, we give the complete classification of full exceptional collections on smooth toric Fano threefolds and fourfolds with Picard rank two. To be precise, we give a partial answer to the conjecture in \cite{Kuz} and \cite{LYY}:…

Algebraic Geometry · Mathematics 2023-03-08 Dae-Won Lee

We classify del Pezzo surfaces with Picard number is equal to one and with four log terminal singular points.

Algebraic Geometry · Mathematics 2025-12-24 Grigory Belousov , DongSeon Hwang

We show that the finiteness of the fundamental groups of the smooth locus of lower dimensional log Fano pairs would imply the finiteness of the local fundamental group of klt singularities. As an application, we verify that the local…

Algebraic Geometry · Mathematics 2019-02-20 Zhiyu Tian , Chenyang Xu

We generalize Givental's Theorem for complete intersections in smooth toric varieties in the Fano case. In particular, we find Gromov--Witten invariants of Fano varieties of dimension $\geq 3$, which are complete intersections in weighted…

Algebraic Geometry · Mathematics 2018-08-07 Victor Przyjalkowski