English
Related papers

Related papers: On isolated log canonical centers

200 papers

We prove that the anti-canonical divisors of weak Fano 3-folds with log canonical singularities are semiample. Moreover, we consider semiampleness of the anti-log canonical divisor of any weak log Fano pair with log canonical singularities.…

Algebraic Geometry · Mathematics 2010-05-10 Yoshinori Gongyo

Given an ambient variety $X$ and a fixed subvariety $Z$ we give sufficient conditions for the existence of a boundary $\Delta$ such that $Z$ is a log canonical center for the pair $(X, \Delta)$. We also show that under some additional…

Algebraic Geometry · Mathematics 2015-12-02 Lorenzo Prelli

The purpose of this note is to give a short proof of a theorem of Koll\'ar that the derived direct image of the canonical sheaf splits into a sum of its cohomology sheaves. This is deduced from a stronger decomposition theorem for direct…

Algebraic Geometry · Mathematics 2013-09-16 Donu Arapura

Let f be a polynomial over the complex numbers with an isolated singularity at 0. We show that the multiplicity and the log canonical threshold of f at 0 are invariants of the link of f viewed as a contact submanifold of the sphere. This is…

Symplectic Geometry · Mathematics 2019-04-17 Mark McLean

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 give an explanation of the $\mathrm{d}\log$-form of the coefficient matrix of canonical differential equations using the projection of ($n$+1)-$\mathrm{d}\log$ forms onto $n$-$\mathrm{d}\log$ forms. This projection is done using the…

High Energy Physics - Theory · Physics 2024-09-20 Jiaqi Chen , Bo Feng

We introduce the class of weakly log canonical singularities, a natural generalization of semi-log canonical singularities. Toric varieties (associated to toric face rings, possibly non-normal or reducible) which have weakly (semi-) log…

Algebraic Geometry · Mathematics 2017-11-02 Florin Ambro

We show that log canonical thresholds of fixed dimension are standardized. More precisely, we show that any sequence of log canonical thresholds in fixed dimension $d$ accumulates in a way which is i) either similar to how standard and…

Algebraic Geometry · Mathematics 2024-06-07 Jihao Liu , Fanjun Meng , Lingyao Xie

We prove that if Y is a hypersurface of degree d in P^n with isolated singularities, then the log canonical threshold of (P^n,Y) is at least min{n/d,1}. Moreover, if d is at least n+1, then we have equality if and only if Y is the…

Algebraic Geometry · Mathematics 2007-05-23 Lawrence Ein , Mircea Mustata

As is well known, the "usual discrepancy" is defined for a normal Q-Gorenstein variety. By using this discrepancy we can define a canonical singularity and a log canonical singularity. In the same way, by using a new notion, Mather-Jacobian…

Algebraic Geometry · Mathematics 2013-10-28 Lawrence Ein , Shihoko Ishii

We prove a general result on the depth of Du Bois complexes of a singular variety. We apply it to prove a conjecture of Mustata-Popa and to study the local cohomological defect, extending results of Ogus and Dao-Takagi over the complex…

Algebraic Geometry · Mathematics 2026-02-06 Andrew Burke

Recent study in K-stability suggests that klt singularities whose local volumes are bounded away from zero should be bounded up to special degeneration. We show that this is true in dimension three, or when the minimal log discrepancies of…

Algebraic Geometry · Mathematics 2023-06-02 Ziquan Zhuang

A theorem is established where the computation of the discrete Conley index for zero dimensional basic sets is given with respect to the dynamical information contained in the associated structure matrices. A classification of the reduced…

Dynamical Systems · Mathematics 2015-04-16 Ketty A. de Rezende , Mariana G. Villapouca

We compute the log canonical thresholds of non-negatively curved singular hermitian metrics on ample linearized line bundles on bi-equivariant group compactifications of complex reductive groups. To this end, we associate to any such metric…

Algebraic Geometry · Mathematics 2020-09-16 Thibaut Delcroix

We show that the log canonical threshold polytopes of varieties with log canonical singularities satisfy the ascending chain condition.

Algebraic Geometry · Mathematics 2020-11-05 Jingjun Han , Zhan Li , Lu Qi

We investigate properties of potentially Du Bois singularities, that is, those that occur on the underlying space of a Du Bois pair. We show that a normal variety $X$ with potentially Du Bois singularities and Cartier canonical divisor…

Algebraic Geometry · Mathematics 2020-11-10 Patrick Graf , Sándor J Kovács

The dual complex of a singularity is defined, up-to homotopy, using resolutions of singularities. In many cases, for instance for isolated singularities, we identify and study a "minimal" representative of the homotopy class that is well…

Algebraic Geometry · Mathematics 2014-03-18 Tommaso de Fernex , János Kollár , Chenyang Xu

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

In this article we prove a local implication of boundedness of Fano varieties. More precisely, we prove that $d$-dimensional $a$-log canonical singularities, with standard coefficients, which admit an $\epsilon$-plt blow-up have minimal log…

Algebraic Geometry · Mathematics 2018-10-25 Joaquín Moraga

We prove that a projective vertical exact log smooth morphism of fs log analytic spaces with a base of log rank one yields polarized log Hodge structures in the canonical way.

Algebraic Geometry · Mathematics 2018-11-21 Taro Fujisawa , Chikara Nakayama