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Related papers: Cox rings of du Val singularities

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We define the equivariant Cox ring of a normal variety with algebraic group action. We study algebraic and geometric aspects of this object and show how it is related to the ordinary Cox ring. Then, we specialize to the case of normal…

Algebraic Geometry · Mathematics 2020-10-27 Antoine Vezier

We investigate deformations of lagrangian manifolds with singularities. We introduce a complex similar to the de Rham-complex whose cohomology calculates deformation spaces. Examples of singular lagrangian varieties are presented and…

Algebraic Geometry · Mathematics 2007-05-23 Duco van Straten , Christian Sevenheck

The Cox rings of del Pezzo surfaces are closely related to the Lie groups E_n. In this paper, we generalize the definition of Cox rings to G- surfaces defined by us earlier, where the Lie groups G=A_n, D_n or E_n. We show that the Cox ring…

Algebraic Geometry · Mathematics 2014-09-09 Naichung Conan Leung , Jiajin Zhang

We continue to study and present concrete examples in characteristic 2 of compound Du Val singularities defined over an algebraically closed field which have one dimensional singular loci but cannot be written as products (a rational double…

Algebraic Geometry · Mathematics 2019-12-19 Masayuki Hirokado

Cox rings are intrinsic objects naturally generalizing homogeneous coordinate rings of projective spaces. A complexity-one horospherical variety is a normal variety equipped with a reductive group action whose general orbit is horospherical…

Algebraic Geometry · Mathematics 2016-12-05 Kevin Langlois , Ronan Terpereau

For a smooth Del Pezzo surface the direct sum of global sections of all isomorphism classes of invertible sheaves on it can be almost canonically endowed with a ring structure, called the Cox ring. We show that in characteristic 0 this ring…

Algebraic Geometry · Mathematics 2007-05-23 Oleg N. Popov

We give an intrinsic characterization of Cox sheaves on Krull schemes in terms of their valuative algebraic properties. We also provide a geometric characterization of their graded relative spectra in terms of good quotients of graded…

Algebraic Geometry · Mathematics 2013-12-19 Benjamin Bechtold

We provide a complete classification of the singularities of cluster algebras of finite cluster type. This extends our previous work about the case of trivial coefficients. Additionally, we classify the singularities of cluster algebras for…

Algebraic Geometry · Mathematics 2025-09-23 Angélica Benito , Eleonore Faber , Hussein Mourtada , Bernd Schober

We extend the Cox-Hu-Keel construction of the Cox rings to any proper birational morphisms of normal noetherian schemes. It allows the representation of any proper birational morphism by a map of schemes with mild singularities with torus…

Algebraic Geometry · Mathematics 2023-02-01 Jarosław Włodarczyk

Cox rings of normal varieties are factorially graded, i.e. homogeneous elements allow a unique decomposition into homogeneous factors. We study this property from an algebraic point of view and give a criterion which in a sense reduces it…

Algebraic Geometry · Mathematics 2012-01-19 Benjamin Bechtold

We introduce a cohomological method to compute Cox rings of hypersurfaces in the ambient space P^1 x P^n, which is more direct than existing methods. We prove that smooth hypersurfaces defined by regular sequences of coefficients are Mori…

Algebraic Geometry · Mathematics 2025-09-19 Andrew Pollock , Atsushi Ito , Balazs Szendroi

We prove a formula for Thom polynomials of Morin (or A_d) singularities in any codimension. We use a combination of the test-curve method of Porteous, and the localization methods in equivariant cohomology. Our formulas are independent of…

Algebraic Topology · Mathematics 2008-12-04 Gergely Berczi , Andras Szenes

We compute symplectic cohomology for Milnor fibres of certain compound Du Val singularities that admit small resolution by using homological mirror symmetry. Our computations suggest a new conjecture that the existence of a small resolution…

Symplectic Geometry · Mathematics 2022-06-09 Jonathan David Evans , Yanki Lekili

We give a proper definition of the multiplicative structure of the following rings: the Cox ring of invertible sheaves on a general algebraic stack; and the Cox ring of rank one reflexive sheaves on a normal and excellent algebraic stack.…

Algebraic Geometry · Mathematics 2024-01-04 Andreas Hochenegger , Elena Martinengo , Fabio Tonini

In the classification of real singularities by Arnold et al. (1985), normal forms, as representatives of equivalence classes under right equivalence, are not always uniquely determined. We describe the complete structure of the equivalence…

Algebraic Geometry · Mathematics 2016-01-18 Magdaleen S. Marais , Andreas Steenpass

We determine the Cox ring of the space of complete rank two collineations.

Algebraic Geometry · Mathematics 2013-05-15 Juergen Hausen , Michael Liebendoerfer

We investigate the Cox ring of a normal complete variety X with algebraic torus action. Our first results relate the Cox ring of X to that of a maximal geometric quotient of X. As a consequence, we obtain a complete description of the Cox…

Algebraic Geometry · Mathematics 2015-03-13 Juergen Hausen , Hendrik Süß

We consider finitely generated normal algebras over an algebraically closed field of characteristic zero that come with a complexity one grading by a finitely generated abelian group such that the conditions of a UFD are satisfied for…

Algebraic Geometry · Mathematics 2013-05-15 Juergen Hausen , Elaine Herppich

We classify the canonical threefold singularities that allow an effective two-torus action. This extends classification results of Mori on terminal threefold singularities and of Ishida and Iwashita on toric canonical threefold…

Algebraic Geometry · Mathematics 2018-07-24 Lukas Braun , Daniel Hättig

We study the equations of universal torsors on rational surfaces.

Algebraic Geometry · Mathematics 2007-05-23 Brendan Hassett , Yuri Tschinkel