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Related papers: Fano type surfaces with large cyclic automorphisms

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We survey some old and new results about acyclic (affine) complex surfaces, also called homology planes. We ask several questions and leave open directions for future research.

Algebraic Geometry · Mathematics 2024-01-12 Rodolfo Aguilar Aguilar

We state a number of conjectures that together allow one to classify a broad class of del Pezzo surfaces with cyclic quotient singularities using mirror symmetry. We prove our conjectures in the simplest cases. The conjectures relate…

We characterize the birational geometry of some hyperk\"ahler fourfolds of Picard rank $3$ obtained as the Fano varieties of lines on cubic fourfolds containing pairs of cubic scrolls. In each of the two cases considered, we identify all of…

Algebraic Geometry · Mathematics 2025-09-10 Corey Brooke , Sarah Frei , Lisa Marquand , Xuqiang Qin

We obtain 866 isomorphism classes of five-dimensional nonsingular toric Fano varieties using a computer program and the database of four-dimensional reflexive polytopes. The algorithm is based on the existence of facets of Fano polytopes…

Algebraic Geometry · Mathematics 2010-02-14 Maximilian Kreuzer , Benjamin Nill

We exhibit a local residual set of surface $C^1$ diffeomorphisms that are continuum-wise expansive but are not expansive. We also exhibit an open and dense set of surface $C^1$ diffeomorphisms where expansiveness implies being Anosov.

Dynamical Systems · Mathematics 2026-03-16 Alfonso Artigue , Bernardo Carvalho , José Cueto

We prove that normal projective surfaces of dense globally $F$-split type (resp. globally $F$-regular type) are of Calabi-Yau type (resp. Fano type).

Algebraic Geometry · Mathematics 2013-05-30 Yoshinori Gongyo , Shunsuke Takagi

The present paper deals with lines contained in a smooth complex cubic threefold. It is well-known that the set of lines of the second type on a cubic threefold is a curve on its Fano surface. Here we give a description of the singularities…

Algebraic Geometry · Mathematics 2022-02-03 Gloire Grace Bockondas , Samuel Boissiere

We establish birational superrigidity for a large class of singular projective Fano hypersurfaces of index one. In the special case of isolated singularities, our result applies for instance to: (1) hypersurfaces with semi-homogeneous…

Algebraic Geometry · Mathematics 2016-04-07 Tommaso de Fernex

We show that every Mori dream space of globally $F$-regular type is of Fano type. As an application, we give a characterization of varieties of Fano type in terms of the singularities of their Cox rings.

Algebraic Geometry · Mathematics 2012-01-06 Yoshinori Gongyo , Shinnosuke Okawa , Akiyoshi Sannai , Shunsuke Takagi

For Fano varieties of various singularities such as canonical and terminal, we construct examples with large Fano index. By low-dimensional evidence, we conjecture that our examples have the largest Fano index for all dimensions.

Algebraic Geometry · Mathematics 2023-08-15 Chengxi Wang

We study weighted Fano fourfolds of K3 type realized as hypersurfaces in weighted projective spaces. Under the additional assumption that the singular locus has dimension at most one, we prove that only finitely many such families exist. We…

Algebraic Geometry · Mathematics 2025-06-24 Valeria Bertini , Francesco Antonio Denisi , Enrico Fatighenti , Annalisa Grossi

We study the homeomorphism types of certain covers of (always orientable) surfaces, usually of infinite-type. We show that every surface with non-abelian fundamental group is covered by every noncompact surface, we identify the universal…

Geometric Topology · Mathematics 2025-08-05 Ian Biringer , Yassin Chandran , Tommaso Cremaschi , Jing Tao , Nicholas G. Vlamis , Mujie Wang , Brandis Whitfield

In this paper, we classify smooth toric Fano 5-folds of index 2. There exist exactly 10 smooth toric Fano 5-folds of index 2 up to isomorphisms.

Algebraic Geometry · Mathematics 2007-05-23 Hiroshi Sato

We prove some general results concerning the size of the group of automorphisms of the Douady space of points on a surface. We then study some properties of the automorphisms coming from an automorphism of the surface, in particular their…

Algebraic Geometry · Mathematics 2009-05-28 Samuel Boissiere

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

In the present paper we discuss coherent sheaves of rank > 1 whose projectivization gives rise to smooth varieties - varieties of this type are also called smooth scrolls. We prove some basic properties of these varieties and we give some…

alg-geom · Mathematics 2008-02-03 Edoardo Ballico , Jaroslaw Wisniewski

We classify all possible automorphism groups of smooth cubic surfaces over an algebraically closed field of arbitrary characteristic. As an intermediate step we also classify automorphism groups of quartic del Pezzo surfaces. We show that…

Algebraic Geometry · Mathematics 2018-10-15 Igor Dolgachev , Alexander Duncan

We classify Enriques surfaces with smooth K3 cover and finite automorphism group in arbitrary positive characteristic. The classification is the same as over the complex numbers except that some types are missing in small characteristics.…

Algebraic Geometry · Mathematics 2017-04-07 Gebhard Martin

We study the cones of q-ample divisors on smooth complex varieties. In favourable cases, we identify a part where the closure of this cone and the nef cone have the same boundary. This is especially interesting for Fano (or almost Fano)…

Algebraic Geometry · Mathematics 2016-02-17 Robert Laterveer

This paper investigates circle patterns with obtuse exterior intersection angles on surfaces of finite topological type. We characterise the images of the curvature maps and establish several equivalent conditions regarding long time…

Geometric Topology · Mathematics 2019-09-10 Huabin Ge , Bobo Hua , Ze Zhou