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Related papers: On G-Fano threefolds

200 papers

We investigate when the fundamental group of the smooth part of a K3 surface or Enriques surface with Du Val singularities, is finite. As a corollary we give an effective upper bound for the order of the fundamental group of the smooth part…

Algebraic Geometry · Mathematics 2007-05-23 J. Keum , D. -Q. Zhang

We show that, unlike del Pezzo surfaces, higher dimensional Fano manifolds do not satisfy in general boundedness properties for their ${\rm CH}_0$ group of $0$-cycles. For example, for quartic threefolds having a point of odd degree, there…

Algebraic Geometry · Mathematics 2025-12-02 Claire Voisin

We show that a non-toric $\mathbb{Q}$-factorial terminal Fano threefold of Picard rank $1$ and Fano index $13$ is a weighted hypersurface of degree $12$ in $\mathbb{P}(3,4,5,6,7)$.

Algebraic Geometry · Mathematics 2026-01-22 Yuri Prokhorov

We describe the Fano scheme of lines on a general cubic threefold containing a plane over a field $k$ of characteristic different from 2. Then, we use the Fano scheme to characterize rationality for such cubic threefolds over nonclosed…

Algebraic Geometry · Mathematics 2023-06-13 Corey Brooke

We study smoothings of Fano threefolds. We prove that the Picard number remains constant in the case of terminal Gorenstein singularities.

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

A Fano-Enriques threefold is a three-dimensional non-Gorenstein Fano variety of index 1 with at most canonical singularities. We study the birational geometry of Fano-Enriques threefolds with terminal cyclic quotient singularities. We…

Algebraic Geometry · Mathematics 2023-01-19 Arman Sarikyan

It is known that there are only finitely many mutation-equivalence classes with a given singularity content, and each of these equivalence classes contains only finitely many minimal polygons. We describe an efficient algorithm to classify…

Algebraic Geometry · Mathematics 2017-03-16 Daniel Cavey , Edwin Kutas

We explore connections between existence of $\Bbbk$-rational points for Fano varieties defined over $\Bbbk$, a subfield of $\mathbb{C}$, and existence of K\"ahler-Einstein metrics on their geometric models. First, we show that geometric…

Algebraic Geometry · Mathematics 2024-11-04 Hamid Abban , Ivan Cheltsov , Takashi Kishimoto , Frederic Mangolte

We prove the boundedness of $n$-complements for surface pairs in a generalized case without restrictions on multiplicities or the Fano type assumption.

Algebraic Geometry · Mathematics 2023-05-31 Xiangze Zeng

We give a criterion of factoriality of a suspension. This allows to construct many examples of flexible affine factorial varieties. In particular, we find a homogeneous affine factorial 3-fold that is not a homogeneous space of an algebraic…

Algebraic Geometry · Mathematics 2026-03-25 Ivan Arzhantsev , Kirill Shakhmatov

We construct well-formed and quasismooth terminal Fano 4-folds of index 1 in low codimension containing at worst isolated orbifold points. We provide a certain classification of these varieties where their images under the anitcanonical…

Algebraic Geometry · Mathematics 2025-06-30 Muhammad Imran Qureshi

We prove existence of flips, special termination, the base point free theorem and, in the case of log general type, the existence of minimal models for F-dlt foliated pairs of co-rank one on a $\mathbb Q$-factorial projective threefold. As…

Algebraic Geometry · Mathematics 2025-09-05 Paolo Cascini , Calum Spicer

We prove that Kahler-Einstein Fano manifolds with finite automorphism groups form Hausdorff moduli algebraic space with only quotient singularities. We also discuss the limits as Q-Fano varieties which should be put on the boundary of its…

Algebraic Geometry · Mathematics 2014-07-01 Yuji Odaka

A conjecture widely attributed to Neumann is that all finite non-desarguesian projective planes contain a Fano subplane. In this note, we show that any finite projective plane of even order which admits an orthogonal polarity contains a…

Combinatorics · Mathematics 2015-10-21 Michael Tait

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 classify birationally rigid orbifold Fano 3-folds of index one defined by $5 \times 5$ Pfaffians. We give a sharp criterion for birational rigidity of these families based on the type of singularities that the varieties admit. Various…

Algebraic Geometry · Mathematics 2022-07-22 Hamid Abban , Takuzo Okada

We investigate some coboundary map associated to a $3$-dimensional terminal singularity which is important in the study of deformations of singular $3$-folds. We prove that this map vanishes only for quotient singularities and a…

Algebraic Geometry · Mathematics 2014-10-30 Taro Sano

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 show that many classical results of the minimal model programme do not hold over an algebraically closed field of characteristic two. Indeed, we construct a three dimensional plt pair whose codimension one part is not normal, a three…

Algebraic Geometry · Mathematics 2018-04-26 Paolo Cascini , Hiromu Tanaka

We describe the automorphism groups of smooth Fano threefolds of rank 2 and degree 28 in the cases where they are finite.

Algebraic Geometry · Mathematics 2024-05-15 Joseph Malbon