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Related papers: Boundedness of complements for generalized pairs

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We prove a boundedness result for klt pairs $(X,B)$ such that $K_X+B\equiv 0$ and $B$ is big. As a consequence we obtain a positive answer to the Effective Iitaka Fibration Conjecture for klt pairs with big boundary.

Algebraic Geometry · Mathematics 2014-10-31 Christopher D. Hacon , Chenyang Xu

We introduce birational strong complete regularity and strong complete regularity, two numerical invariants for pairs of (relative) Fano type. They are defined using variants of qdlt Fano type models and the dimension of the dual complex of…

Algebraic Geometry · Mathematics 2026-03-05 Jihao Liu , Konstantin Loginov

We prove a conjecture of Batryev which states that the family of all Fano varieties with kawamata log terminal singularities and fixed index, forms a bounded family.

Algebraic Geometry · Mathematics 2009-09-29 James McKernan

We establish a uniform bound for the Castelnuovo-Mumford regularity of associated graded rings of parameter ideals in a generalized Cohen-Macaulay ring. As consequences, we obtain uniform bounds for the relation type and the postulation…

Commutative Algebra · Mathematics 2007-05-23 Cao Huy Linh , Ngo Viet Trung

We prove several boundedness results for log Fano pairs with certain K-stability. In particular, we prove that K-semistable log Fano pairs of Maeda type form a log bounded family. We also compute K-semistable domains for some examples.

Algebraic Geometry · Mathematics 2025-01-07 Konstantin Loginov , Chuyu Zhou

In this note, we survey some recent developments in birational geometry concerning the boundedness of algebraic varieties. We delineate a strategy to extend some of these results to the case of generalized pairs, first introduced by Birkar…

Algebraic Geometry · Mathematics 2022-03-02 Stefano Filipazzi , Roberto Svaldi

A definable set in a pair (K, k) of algebraically closed fields is co-analyzable relative to the subfield k of the pair if and only if it is almost internal to k. To prove this and some related results for tame pairs of real closed fields…

Logic · Mathematics 2017-07-13 Leonardo Angel , Lou van den Dries

This survey paper reports on work of Birkar, who confirmed a long-standing conjecture of Alexeev and Borisov-Borisov: Fano varieties with mild singularities form a bounded family once their dimension is fixed. Following Prokhorov-Shramov,…

Algebraic Geometry · Mathematics 2021-02-02 Stefan Kebekus

Theory of $n$-complements with applications is presented.

Algebraic Geometry · Mathematics 2020-12-14 V. V. Shokurov

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

Coboundary expansion (with $\mathbb{F}_2$ coefficients), and variations on it, have been the focus of intensive research in the last two decades. It was used to study random complexes, property testing, and above all Gromov's topological…

Group Theory · Mathematics 2024-04-02 Michael Chapman , Alexander Lubotzky

The main purpose of this article is to prove that the family of all Fano threefolds with log-terminal singularities with bounded index is bounded.

alg-geom · Mathematics 2008-02-03 A. Borisov

We survey recent results on the boundedness of the moduli functor of stable pairs

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

In this paper we investigate various properties of generalised pairs in families, especially boundedness of several kinds. We show that many statements for usual pairs do not hold for generalised pairs. In particular, we construct an…

Algebraic Geometry · Mathematics 2022-04-25 Caucher Birkar , Christopher D. Hacon

We study the topology of the complements of discriminants of simple real boundary singularities by counting the connected components of these sets and assigning to them certain topological characteristics. Results of this paper serve as a…

Algebraic Geometry · Mathematics 2022-09-07 M. A. Gudiev

We give a necessary and sufficient condition for a generalized Bott manifold to be Fano or weak Fano. As a consequence we characterize Fano Bott manifolds.

Algebraic Geometry · Mathematics 2018-11-16 Yusuke Suyama

Kobayashi-Ochiai proved that the set of dominant maps from a fixed variety to a fixed variety of general type is finite. We prove the natural extension of their finiteness theorem to Campana's orbifold pairs.

Algebraic Geometry · Mathematics 2023-08-03 Finn Bartsch , Ariyan Javanpeykar

In this paper, we consider mixed sums of generalized polygonal numbers. Specifically, we obtain a finiteness condition for universality of such sums; this means that it suffices to check representability of a finite subset of the positive…

Number Theory · Mathematics 2023-05-25 Ben Kane , Zichen Yang

We prove existence of positive solutions to a nonlinear fractional boundary value problem. Then, under some mild assumptions on the nonlinear term, we obtain a smart generalization of Lyapunov's inequality. The new results are illustrated…

Classical Analysis and ODEs · Mathematics 2016-10-19 Amar Chidouh , Delfim F. M. Torres

We show that the isomorphism induced by the inclusion of pairs $(X,\emptyset)\subset (X,Y)$ between the relative bounded cohomology of $(X,Y)$ and the bounded cohomology of $X$ is isometric in degree at least 2 if the fundamental group of…