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Related papers: Potential log canonical centers

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We show that any union of slc strata of a Fano log pair with semi-log canonical singularities is simply connected. In particular, Fano log pairs with semi-log canonical singularities are simply connected, which confirms a conjecture of the…

Algebraic Geometry · Mathematics 2017-12-12 Osamu Fujino , Wenfei Liu

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

The purpose of this article is to develop techniques for estimating basis log canonical thresholds on logarithmic surfaces. To that end, we develop new local intersection estimates that imply log canonicity. Our main motivation and…

Algebraic Geometry · Mathematics 2024-11-22 Ivan A. Cheltsov , Yanir A. Rubinstein , Kewei Zhang

We prove upper bounds for the spread, the Lindel\"of number and the weak Lindel\"of number of the $G_\delta$-topology on a topological space and apply a few of our bounds to give a short proof to a recent result of Juh\'asz and van Mill…

General Topology · Mathematics 2017-07-18 Angelo Bella , Santi Spadaro

We prove a result on the inversion of adjunction for log canonical pairs that generalizes Kawakita's result to log canonical centers of arbitrary codimension.

Algebraic Geometry · Mathematics 2012-02-03 Christopher D. Hacon

For a smooth germ of algebraic variety $(X,0)$ and a hypersurface $(f=0)$ in $X$, with an isolated singularity at $0$, Teissier conjectured a lower bound for the Arnold exponent of $f$ in terms of the Arnold exponent of a hyperplane section…

Algebraic Geometry · Mathematics 2021-07-07 Eva Elduque , 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

Let $X$ be a compact metric space and let $|A|$ denote the cardinality of a set $A$. We prove that if $f\colon X\to X$ is a homeomorphism and $|X|=\infty$ then for all $\delta>0$ there is $A\subset X$ such that $|A|=4$ and for all $k\in Z$…

Dynamical Systems · Mathematics 2014-04-03 Alfonso Artigue

In previous work, the first three authors conjectured that the ring of regular functions on a natural class of affine log Calabi-Yau varieties (those with maximal boundary) has a canonical vector space basis parameterized by the integral…

Algebraic Geometry · Mathematics 2016-10-31 Mark Gross , Paul Hacking , Sean Keel , Maxim Kontsevich

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.…

Algebraic Geometry · Mathematics 2025-06-25 Raf Cluckers , János Kollár , Mircea Mustaţă

Consider a log canonical pair $(X,B)$ such that there is a Cartier divisor $D$ for which $T_X(-\log B) \otimes \mathcal O(D)$ is locally free and globally generated. Let $\mathcal F$ be a log canonical foliation of rank 1 on $X$. We prove…

Algebraic Geometry · Mathematics 2026-04-10 Calum Spicer , Luca Tasin

We aim to analyze the relation between two random vectors that may potentially have both different number of attributes as well as realizations, and which may even not have a joint distribution. This problem arises in many practical…

Machine Learning · Statistics 2015-11-12 Hoang-Vu Nguyen , Jilles Vreeken

In this paper, we show that the depth of an isolated log canonical center is determined by the cohomology of the -1 discrepancy diviors over it. A similar result also holds for normal isolated Du Bois singularities.

Algebraic Geometry · Mathematics 2015-11-03 Chih-Chi Chou

We prove that for log canonical foliations which are birationally bounded by algebraically integrable families, the set of their volumes satisfies the DCC. This answers a special case of a question posed by Cascini, Hacon, and Langer. As a…

Algebraic Geometry · Mathematics 2025-12-29 Zhixiu Fan

Let G and K be groupoids. We present the notion of a (G_{\alpha},K_{\beta})-set and we prove a duality theorem in this context, which extends the duality theorem for graded algebras by groups. For A a unital G-graded algebra and X a finite…

Rings and Algebras · Mathematics 2021-11-30 Saradia Della Flora , Daiana Flôres , Andrea Morgado , Thaísa Tamusiunas

The quotient variety associated to a permutation representation of a finite group has only canonical singularities in arbitrary characteristic. Moreover, the log pair associated to such a representation is Kawamata log terminal except in…

Algebraic Geometry · Mathematics 2026-05-27 Takehiko Yasuda

In this paper, for any pair $(\zeta, \xi)$ of Newton polygons with $\zeta \prec \xi$, we construct a concrete specialization from the minimal $p$-divisible group of $\xi$ to the minimal $p$-divisible group of $\zeta$ by a beautiful…

Algebraic Geometry · Mathematics 2018-04-11 Nobuhiro Higuchi , Shushi Harashita

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 lct(f, J_f^2)>1 if and only if the hypersurface defined by f has rational singularities. Moreover, if this is not…

Algebraic Geometry · Mathematics 2022-02-23 Raf Cluckers , Mircea Mustata

Given an NQC log canonical generalized pair $(X,B+M)$ whose underlying variety $X$ is not necessarily $\mathbb{Q}$-factorial, we show that one may run a $(K_X+B+M)$-MMP with scaling of an ample divisor which terminates, provided that…

Algebraic Geometry · Mathematics 2025-09-19 Nikolaos Tsakanikas , Lingyao Xie

Kang, Kashiwara, Kim and Oh have proved that cluster monomials lie in the dual canonical basis, under a symmetric type assumption. This involves constructing a monoidal categorification of a quantum cluster algebra using representations of…

Quantum Algebra · Mathematics 2021-12-09 Peter J. McNamara