English
Related papers

Related papers: Bounds for log canonical thresholds with applicati…

200 papers

Let T_n denote the set of log canonical thresholds of pairs (X,Y), with X a nonsingular variety of dimension n, and Y a nonempty closed subscheme of X. Using non-standard methods, we show that every limit of a decreasing sequence in T_n…

Algebraic Geometry · Mathematics 2009-02-02 Tommaso de Fernex , Mircea Mustata

We give an upper bound for the degree of rational curves in a family that covers a given birational ruled surface in projective space. The upper bound is stated in terms of the degree, sectional genus and arithmetic genus of the surface. We…

Algebraic Geometry · Mathematics 2021-03-09 Niels Lubbes

The log canonical thresholds of irreducible quasi-ordinary hypersurface singularities are computed, using an explicit list of pole candidates for the motivic zeta function found by the last two authors.

Algebraic Geometry · Mathematics 2011-05-16 Nero Budur , Pedro D. González-Pérez , Manuel González Villa

Building on results of Koll\'ar, we prove Shokurov's ACC Conjecture for log canonical thresholds on smooth varieties, and more generally, on varieties with quotient singularities.

Algebraic Geometry · Mathematics 2009-01-09 Lawrence Ein , Mircea Mustata

On smooth threefolds, the ACC for minimal log discrepancies is equivalent to the boundedness of the log discrepancy of some divisor which computes the minimal log discrepancy. We reduce it to the case when the boundary is the product of a…

Algebraic Geometry · Mathematics 2018-03-08 Masayuki Kawakita

We prove lower bounds for the minimum distance of algebraic geometry codes over surfaces whose canonical divisor is either nef or anti-strictly nef and over surfaces without irreducible curves of small genus. We sharpen these lower bounds…

Algebraic Geometry · Mathematics 2020-03-04 Yves Aubry , Elena Berardini , Fabien Herbaut , Marc Perret

We prove that the log canonical threshold of the base ideal of a complete linear system on a complex abelian variety is $\ge 1$, and equality holds if and only if the base locus has divisorial components. Consequently the same assertions…

Algebraic Geometry · Mathematics 2025-12-29 Giuseppe Pareschi

We compute global log canonical thresholds of some smooth Fano threefolds.

Algebraic Geometry · Mathematics 2009-02-08 Ivan Cheltsov , Constantin Shramov

Let $(X,\mathcal{F})$ be a foliated surface over the complex numbers. We study the variation of $\epsilon$-adjoint singularities, defined by the adjoint divisor $K_{\mathcal{F}}+\epsilon K_X$ ($\epsilon>0$), and analyze their stability as…

Algebraic Geometry · Mathematics 2026-03-04 Shi Xu

Shokurov conjectured that the set of all log canonical thresholds on varieties of bounded dimension satisfies the ascending chain condition. In this paper we prove that the conjecture holds for log canonical thresholds on smooth varieties…

Algebraic Geometry · Mathematics 2019-12-19 Tommaso de Fernex , Lawrence Ein , Mircea Mustata

It is shown that the log-canonical threshold of a curve with an isolated singularity is computed by the term ideal of the curve in a suitable system of local parameters at the singularity. The proof uses the Enriques diagram of the…

Algebraic Geometry · Mathematics 2007-07-06 Marian Aprodu , Daniel Naie

We study log canonical thresholds on quartic threefolds, quintic fourfolds, and double spaces. As an application, we show that they have a Kaehler-Einstein metric if they are general.

Algebraic Geometry · Mathematics 2015-01-05 Ivan Cheltsov , Jihun Park , Joonyeong Won

In this paper, we show the log canonical threshold values of the surfaces which has du Val type singularities.These surfaces can be interpreted as statistical or machine learning models. The results of $A_n, D_n, E_6, E_7$ and $E_8$ are…

Algebraic Geometry · Mathematics 2023-12-29 Yoshinori Watanabe

Let $B$ be a smooth projective curve of genus $g$, and $S \subset B$ be a finite subset of cardinality $s$. We give an effective upper bound on the number of deformation types of admissible families of canonically polarized manifolds of…

Algebraic Geometry · Mathematics 2011-05-18 Gordon Heier , Shigeharu Takayama

We show that if a divisor centered over a point on a smooth surface computes a minimal log discrepancy, then the divisor also computes a log canonical threshold. To prove the result, we study the asymptotic log canonical threshold of the…

Algebraic Geometry · Mathematics 2017-06-08 Harold Blum

We prove birational superrigidity of Fano double hypersurfaces of index one with quadratic and multi-quadratic singularities, satisfying certain regularity conditions, and give an effective explicit lower bound for the codimension of the…

Algebraic Geometry · Mathematics 2018-12-31 Thomas Eckl , Aleksandr Pukhlikov

We prove a conjecture due to V.V. Shokurov on the boundedness of $\epsilon$-log canonical complements on surfaces. As an application we give a new proof to the boundedness of weak log Fano surfaces.

Algebraic Geometry · Mathematics 2007-05-23 Caucher Birkar

Let S be a minimal complex surface of general type with irregularity q>=2 and let C be an irreducible curve of geometric genus g contained in S. Assume that C is "Albanese defective", i.e., that the image of C via the Albanese map does not…

Algebraic Geometry · Mathematics 2012-04-20 Margarida Mendes Lopes , Rita Pardini

In this article we prove the following boundedness result: Fix a DCC set $I\subset [0, 1]$. Let $\mathfrak{D}$ be the set of all log pairs $(X, \Delta)$ satisfying the following properties: (i) $X$ is a projective surface defined over an…

Algebraic Geometry · Mathematics 2020-11-10 Omprokash Das

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