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Related papers: Shokurov's ACC Conjecture for log canonical thresh…

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We show that generalized log canonical thresholds for complex analytic spaces satisfy the ACC and we characterize the accumulation points.

Algebraic Geometry · Mathematics 2023-03-03 Christopher Hacon , Lingyao Xie

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

A widely believed conjecture predicts that curves of bounded geometric genus lying on a variety of general type form a bounded family. One may even ask whether the canonical degree of a curve $C$ in a variety of general type is bounded from…

Algebraic Geometry · Mathematics 2018-09-25 Pascal Autissier , Antoine Chambert-Loir , Carlo Gasbarri

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 discuss a difference between the rational and the real non-vanishing conjecture for pseudo-effective log canonical divisors of log canonical pairs. We also show the log non-vanishing theorem for rationally connected varieties under…

Algebraic Geometry · Mathematics 2012-05-30 Yoshinori Gongyo

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

The minimal log discrepancy is an invariant of singularities that plays an important role in the birational classification of algebraic varieties. Shokurov conjectured that the minimal log discrepancy can always be bounded from above in…

Algebraic Geometry · Mathematics 2025-11-24 Leandro Meier

We generalize the formula for the log canonical threshold(LCT) of plane curves over the complex numbers to arbitrary characteristics. Our proof relies purely on valuation theory, instead of on the theory of $D$-modules.

Algebraic Geometry · Mathematics 2026-02-03 Chih-Kuang Lee

We obtain a correct generalization of Shokurov's non-vanishing theorem for log canonical pairs. It implies the base point free theorem for log canonical pairs. We also prove the rationality theorem for log canonical pairs. As a corollary,…

Algebraic Geometry · Mathematics 2009-12-01 Osamu Fujino

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

We consider the following conjecture: on a klt germ (X,x), for every finite set I there is a positive integer N with the property that for every R-ideal J on X with exponents in I, there is a divisor E over X that computes the minimal log…

Algebraic Geometry · Mathematics 2024-04-30 Mircea Mustata , Yusuke Nakamura

It was conjectured by Tian that the global log canonical threshold (known as the $\alpha$-invariant) is equal to the level $k$ log canonical threshold (known as the $\alpha_k$-invariant) for all sufficiently large $k$. A weaker folklore…

Algebraic Geometry · Mathematics 2024-12-04 Chenzi Jin

We use intersection theory, degeneration techniques and jet schemes to study log canonical thresholds. Our first result gives a lower bound for the log canonical threshold of a pair in terms of the log canonical threshold of the image by a…

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

We prove an upper bound on the log canonical threshold of a hypersurface that satisfies a certain power condition and use it to prove several generalizations of Igusa's conjecture on exponential sums, with the log-canonical threshold in the…

Number Theory · Mathematics 2019-03-20 Raf Cluckers , Mircea Mustaţǎ , Kien Huu Nguyen

In this paper, we prove a `cut-by-curves criterion' for an overconvergent isocrystal on a smooth variety over a field of characteristic $p>0$ to extend logarithmically to its smooth compactification whose complement is a strict normal…

Number Theory · Mathematics 2009-06-25 Atsushi Shiho

We prove a conjecture of Shokurov which characterises toric varieties using log pairs.

Algebraic Geometry · Mathematics 2018-05-23 Morgan Brown , James McKernan , Roberto Svaldi , Hong Zong

We generalize the rationality theorem of the accumulation points of log canonical thresholds which was proved by Hacon, M\textsuperscript{c}Kernan, and Xu. Further, we apply the rationality to the ACC problem on the minimal log…

Algebraic Geometry · Mathematics 2024-04-30 Yusuke Nakamura

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

If $X$ is an algebraic variety with at worst canonical singularities and $S$ is a $\Q$-Cartier hypersurface in $X$, the canonical threshold of the pair $(X,S)$ is the supremum of $c\in\R$ such that the pair $(X,cS)$ is canonical. We show…

Algebraic Geometry · Mathematics 2016-03-15 D. A. Stepanov

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