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相关论文: Log Canonical Thresholds and Generalized Eckardt P…

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We generalize the following result of White: Suppose $N$ is a compact, strictly convex domain in $\RR^3$ with smooth boundary. Let $\Sigma$ be a compact 2-manifold with boundary. Then a generic smooth curve $\Gamma\cong \partial\Sigma$ in…

微分几何 · 数学 2009-05-18 David Hoffman , Brian White

By a theorem of Wahl, the canonically embedded curves which are hyperplane section of K3 surfaces are distinguished by the non-surjectivity of their Wahl map. In this paper we address the problem of distinguishing hyperplane sections of…

代数几何 · 数学 2010-01-28 Elisabetta Colombo , Paola Frediani , Giuseppe Pareschi

We compute a canonical circular-arc representation for a given circular-arc (CA) graph which implies solving the isomorphism and recognition problem for this class. To accomplish this we split the class of CA graphs into uniform and…

数据结构与算法 · 计算机科学 2018-02-02 Maurice Chandoo

The LCS locus is an essential ingredient in the proof of fundamental results of Log Minimal Model Program, such as nonvanishing and base point freeness theorems. We prove in this paper that the LCS locus of a log canonical variety has…

代数几何 · 数学 2007-05-23 Florin Ambro

Given a local field $F$ of positive characteristic, an $F$-analytic manifold $X$ and an analytic function $f:X\rightarrow F$, the $F$-analytic log-canonical threshold $\mathrm{lct}_{F}(f;x_{0})$ is the supremum over the values $s\geq0$ such…

代数几何 · 数学 2025-11-04 Itay Glazer , Yotam I. Hendel

We classify log-canonical pairs $(X, \Delta)$ of dimension two with $K_X+\Delta$ an ample Cartier divisor with $(K_X+\Delta)^2=1$, giving some applications to stable surfaces with $K^2=1$. A rough classification is also given in the case…

代数几何 · 数学 2015-08-19 Marco Franciosi , Rita Pardini , Sönke Rollenske

In this article we exhibit certain projective degenerations of smooth $K3$ surfaces of degree $2g-2$ in $\Bbb P^g$ (whose Picard group is generated by the hyperplane class), to a union of two rational normal scrolls, and also to a union of…

alg-geom · 数学 2009-10-22 Ciro Ciliberto , Angelo Lopez , Rick Miranda

We generalize Miyanishi's theory of almost minimal models of log smooth surfaces with reduced boundary to the case of arbitrary log surfaces defined over an algebraically closed field. Given an MMP run of a log surface $(X,D)$ we define and…

代数几何 · 数学 2024-02-13 Karol Palka

We classify all rational maps $H \in K(x)^n$ for which ${\rm trdeg}_K K(tH_1,tH_2,\ldots,tH_n) \le 2$, where $K$ is any field and $t$ is another indeterminate. Furthermore, we classify all such maps for which additionally $JH \cdot H = {\rm…

交换代数 · 数学 2017-11-06 Michiel de Bondt

In this article, we investigate F-pure thresholds of polynomials that are homogeneous under some N-grading, and have an isolated singularity at the origin. We characterize these invariants in terms of the base p expansion of the…

Let $X\subset\mathbb P^{n+1}$ be a smooth complex projective hypersurface. In this paper we show that, if the degree of $X$ is large enough, then there exist global sections of the bundle of invariant jet differentials of order $n$ on $X$,…

代数几何 · 数学 2017-04-04 Simone Diverio

We show that if $f$ is a nonzero, noninvertible function on a smooth complex variety $X$ and $J_f$ is the Jacobian ideal of $f$, then ${\rm lct}(f,J_f^2)>1$ if and only if the hypersurface defined by $f$ has rational singularities.…

代数几何 · 数学 2025-06-25 Raf Cluckers , János Kollár , Mircea Mustaţă

We study hypersurfaces with fractional mean curvature in N-dimensional Euclidean space. These hypersurfaces are critical points of the fractional perimeter under a volume constraint. We use local inversion arguments to prove existence of…

偏微分方程分析 · 数学 2018-04-06 Ignace Aristide Minlend , Alassane Niang , El Hadji Abdoulaye Thiam

This paper is the continuation of the research of the author and his colleagues of the {\it canonical} decomposition of graphs. The idea of the canonical decomposition is to define the binary operation on the set of graphs and to represent…

组合数学 · 数学 2016-07-19 Pavel Skums

We prove that a component of the closure of the set of star points on a hypersurface X of degree d>2 in N-dimensional projective space is linear. Afterwards, we focus on the case where the component is of maximal dimension N-2 and the case…

代数几何 · 数学 2009-09-10 Filip Cools , Marc Coppens

Let $V$ be a smooth projective 3-fold of general type. Denote by $K^{3}$, a rational number, the self-intersection of the canonical sheaf of any minimal model of $V$. One defines $K^{3}$ as a canonical volume of $V$. The paper is devoted to…

代数几何 · 数学 2007-10-25 Lei Zhu

In a first part of this paper, we prove constancy of the canonical graded Betti table among the smooth curves in linear systems on Gorenstein weak Fano toric surfaces. In a second part, we show that Green's canonical syzygy conjecture holds…

代数几何 · 数学 2019-04-30 Wouter Castryck , Filip Cools , Jeroen Demeyer , Alexander Lemmens

We prove that the largest accumulation point of the set $\mathcal{T}_3$ of all three-dimensional log canonical thresholds $c(X,F)$ is 5/6.

代数几何 · 数学 2010-05-04 Yuri Prokhorov

A good canonical projection of a surface $S$ of general type is a morphism to the 3-dimensional projective space P^3 given by 4 sections of the canonical line bundle. To such a projection one associates the direct image sheaf F of the…

代数几何 · 数学 2007-05-23 Fabrizio Catanese , Frank Olaf Schreyer

For X = R, C, or H it is well known that cusp cross-sections of finite volume X-hyperbolic (n+1)-orbifolds are flat n-orbifolds or almost flat orbifolds modelled on the (2n+1)-dimensional Heisenberg group N_{2n+1} or the (4n+3)-dimensional…

几何拓扑 · 数学 2014-10-01 D. B. McReynolds