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Related papers: Remarks on the abundance conjecture

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Let $\Lambda = \mathrm{SL}_2(\Bbb Z)$ be the modular group and let $c_n(\Lambda)$ be the number of congruence subgroups of $\Lambda$ of index at most $n$. We prove that $\lim\limits_{n\to \infty} \frac{\log c_n(\Lambda)}{(\log n)^2/\log\log…

Group Theory · Mathematics 2009-11-10 D. Goldfeld , A. Lubotzky , N. Nikolov , L. Pyber

We show that the family of semi log canonical pairs with ample log canonical class and with fixed volume is bounded.

Algebraic Geometry · Mathematics 2017-09-22 Christopher Hacon , James McKernan , Chenyang Xu

We prove $\mathbb{R}$-boundary divisor versions of results proved by Birkar or Hacon-Xu on special kinds of the relative log minimal model program.

Algebraic Geometry · Mathematics 2017-04-05 Kenta Hashizume

In this article we prove a finiteness result on the number of log minimal models for $3$-folds in char $p>5$. We then use this result to prove a version of Batyrev's conjecture on the structure of nef cone of curves on $3$-folds in…

Algebraic Geometry · Mathematics 2018-09-17 Omprokash Das

For a birational log Fano contraction, it is conjectured an inequality between the dimension of its exceptional locus and the minimal log discrepancy over the locus. The conjecture follows from the existence of the flip for the contraction…

Algebraic Geometry · Mathematics 2016-09-07 V. V. Shokurov

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

Let $(X,\Delta)$ be a 4-dimensional log variety which is proper over the field of complex numbers and with only divisorial log terminal singularities. The log canonical divisor $K_X+\Delta$ is semi-ample, if it is nef (numerically…

Algebraic Geometry · Mathematics 2007-05-23 Shigetaka Fukuda

In this paper, we prove abundance for 3-folds with non-trivial Albanese maps, over an algebraically closed field of characteristic $p > 5$.

Algebraic Geometry · Mathematics 2019-10-09 Lei Zhang

We prove the base point free theorem for big line bundles on a three-dimensional log canonical projective pair defined over the algebraic closure of a finite field.

Algebraic Geometry · Mathematics 2016-01-20 Diletta Martinelli , Yusuke Nakamura , Jakub Witaszek

We completely prove the ACC for minimal log discrepancies on smooth threefolds. It implies on smooth threefolds the ACC for a-lc thresholds, the uniform m-adic semi-continuity of minimal log discrepancies and the boundedness of the log…

Algebraic Geometry · Mathematics 2023-12-29 Masayuki Kawakita

We study the behavior of generalized lc pairs with $\mathrm{\textbf b}$-log abundant nef part, a meticulously designed structure on algebraic varieties. We show that this structure is preserved under the canonical bundle formula and…

Algebraic Geometry · Mathematics 2022-02-25 Junpeng Jiao , Jihao Liu , Lingyao Xie

We prove that the log canonical ring of a klt pair of dimension $3$ with $\mathbb{Q}$-boundary over an algebraically closed field of characteristic $p>5$ is finitely generated. In the process we prove log abundance for such pairs in the…

Algebraic Geometry · Mathematics 2016-05-02 Joe Waldron

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…

Algebraic Geometry · Mathematics 2007-05-23 Florin Ambro

We show that for every $r \geq 1$, and all $r$ distinct (sufficiently large) primes $p_1,..., p_r > p_0(r)$, there exist infinitely many integers $n$ such that ${2n \choose n}$ is divisible by these primes to only low multiplicity. From a…

Number Theory · Mathematics 2023-01-09 Ernie Croot , Hamed Mousavi , Maxie Schmidt

We construct examples of contingency tables on $n$ binary random variables where the gap between the linear programming lower/upper bound and the true integer lower/upper bounds on cell entries is exponentially large. These examples provide…

Optimization and Control · Mathematics 2007-06-13 Seth Sullivant

We prove that the log canonical thresholds of a large class of binomial ideals, such as complete intersection binomial ideals and the defining ideals of space monomial curves, are computable by linear programming.

Algebraic Geometry · Mathematics 2009-04-09 Takafumi Shibuta , Shunsuke Takagi

Let $p_n$ denote the $n$th prime and $g_n:=p_{n+1}-p_n$ the $n$th prime gap. We demonstrate the existence of infinitely many values of $n$ for which $g_n>g_{n+1}>\cdots>g_{n+m}$ with $m\gg \log\log\log n$ and similarly for the reversed…

Number Theory · Mathematics 2016-04-12 D. K. L. Shiu

In this paper we prove the Zariski-Lipman conjecture for log canonical spaces.

Algebraic Geometry · Mathematics 2017-05-17 Stéphane Druel

We show that, for nonsingular projective 4-folds V of general type with geometric genus $p_g\geq 2$, the 33-canonical map is birational onto the image and the canonical volume has the lower bound $1/520$, which improves a previous theorem…

Algebraic Geometry · Mathematics 2021-01-19 Jianshi Yan

We prove that many of the results of the LMMP hold for $3$-folds over fields of characteristic $p>5$ which are not necessarily perfect. In particular, the existence of flips, the cone theorem, the contraction theorem for birational extremal…

Algebraic Geometry · Mathematics 2022-08-22 Omprokash Das , Joe Waldron