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Related papers: A boundedness theorem for cone singularities

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The main purpose of this article is to prove that the family of all Fano threefolds with log-terminal singularities with bounded index is bounded.

alg-geom · Mathematics 2008-02-03 A. Borisov

In this article we study conjectures regarding normalized volume and boundedness of singularities. We focus on singularities with a torus action of complexity 1, threefold singularities, and hypersurface singularities. Given a real value…

Algebraic Geometry · Mathematics 2023-03-29 Yuchen Liu , Joaquín Moraga , Hendrik Süß

We prove that in any fixed dimension, K-semistable log Fano cone singularities whose volumes are bounded from below by a fixed positive number form a bounded set. As a consequence, we show that the set of local volumes of klt singularities…

Algebraic Geometry · Mathematics 2024-08-22 Chenyang Xu , Ziquan Zhuang

We study families of spherical metrics on the flat torus $E_{\tau}$ $=$ $\mathbb{C}/\Lambda_{\tau}$ with blow-up behavior at prescribed conical singularities at $0$ and $\pm p$, where the cone angle at $0$ is $6\pi$, and at $\pm p$ is…

Differential Geometry · Mathematics 2025-09-15 Ting-Jung Kuo , Xuanpu Liang , Ping-Hsiang Wu

We classify the singularities of a surface ruled by conics: they are rational double points of type $A_n$ or $D_n$. This is proved by showing that they arise from a precise series of blow-ups of a suitable surface geometrically ruled by…

Algebraic Geometry · Mathematics 2012-11-07 Michela Brundu , Gianni Sacchiero

We study special Lagrangian cones in $\C^n$ with isolated singularities. Our main result constructs an infinite family of special Lagrangian cones in $\C^3$ each of which has a toroidal link. We obtain a detailed geometric description of…

Differential Geometry · Mathematics 2007-05-23 Mark Haskins

Standard singularity theorems are proven in Lorentzian manifolds of arbitrary dimension n if they contain closed trapped submanifolds of arbitrary co-dimension. By using the mean curvature vector to characterize trapped submanifolds, a…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Gregory J. Galloway , José M. M. Senovilla

We prove the cone theorem for varieties with LCIQ singularities using deformation theory of stable maps into Deligne-Mumford stacks. We also obtain a sharper bound on $-(K_X+D)$-degree of $(K_X+D)$-negative extremal rays for projective…

Algebraic Geometry · Mathematics 2009-08-20 Jiun-Cheng Chen , Hsian-Hua Tseng

Let $X$ be a smooth projective variety over the complex numbers. One knows by the Cone Theorem that the closed cone of curves of $X$ is rational polyhedral whenever $c_1(X)$ is ample. For varieties $X$ such that $c_1(X)$ is not ample,…

alg-geom · Mathematics 2007-05-23 Thomas Bauer

In this paper, we study tropicalisations of families of curves with a singularity in a fixed point. The tropicalisation of such a family is a linear tropical variety. We describe its maximal dimensional cones using results about linear…

Algebraic Geometry · Mathematics 2012-03-27 Hannah Markwig , Thomas Markwig , Eugenii Shustin

We construct and classify, in the case of two complex dimensions, the possible tangent cones at points of limit spaces of non-collapsed sequences of K\"ahler-Einstein metrics with cone singularities.

Differential Geometry · Mathematics 2021-10-26 Martin de Borbon

Cone spherical metrics are conformal metrics with constant curvature one and finitely many conical singularities on compact Riemann surfaces. A cone spherical metric is called irreducible if each developing map of the metric does not have…

Algebraic Geometry · Mathematics 2022-10-11 Lingguang Li , Jijian Song , Bin Xu

A conic bundle is a contraction $X\to Z$ between normal varieties of relative dimension $1$ such that $-K_X$ is relatively ample. We prove a conjecture of Shokurov which predicts that, if $X\to Z$ is a conic bundle such that $X$ has…

Algebraic Geometry · Mathematics 2022-07-12 Jingjun Han , Chen Jiang , Yujie Luo

We give canonical resolutions of singularities of several cone varieties arising from invariant theory. We establish a connection between our resolutions and resolutions of singularities of closure of conjugacy classes in classical Lie…

Algebraic Geometry · Mathematics 2007-05-23 Weiqiang Wang

We study the geometry of warped cones over free, minimal isometric group actions and related constructions of expander graphs. We prove a rigidity theorem for the coarse geometry of such warped cones: Namely, if a group has no abelian…

Metric Geometry · Mathematics 2018-01-09 David Fisher , Thang Nguyen , Wouter van Limbeek

For every proper convex cone $K \subset \mathbb R^3$ there exists a unique complete hyperbolic affine 2-sphere with mean curvature $-1$ which is asymptotic to the boundary of the cone. Two cones are associated if the corresponding affine…

Differential Geometry · Mathematics 2021-01-12 Roland Hildebrand

We study log canonical thresholds (also called global log canonical threshold or $\alpha$-invariant) of $\mathbb{R}$-linear systems. We prove existence of positive lower bounds in different settings, in particular, proving a conjecture of…

Algebraic Geometry · Mathematics 2020-12-02 Caucher Birkar

We study the singularities of Legendrian subvarieties of contact manifolds in the complex-analytic category and prove two rigidity results. The first one is that Legendrian singularities with reduced tangent cones are contactomorphically…

Algebraic Geometry · Mathematics 2023-06-22 Jun-Muk Hwang

We establish uniqueness and regularity results for tangent cones (at a point or at infinity) with isolated singularities arising from a given immersed stable minimal hypersurface with suitably small (non-immersed) singular set. In…

Differential Geometry · Mathematics 2024-01-30 Nick Edelen , Paul Minter

A singularity in characteristic zero is said to be of dense F-pure type if its modulo p reduction is locally F-split for infinitely many p. We prove that if $x \in X$ is an isolated log canonical singularity with $\mu(x \in X) \le 2$ (see…

Algebraic Geometry · Mathematics 2012-07-03 Osamu Fujino , Shunsuke Takagi
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