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Related papers: Minimal log discrepancy and orbifold curves

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We consider weak Fano manifolds with small contractions obtained by blowing up successively curves and subvarieties of codimension 2 in products of projective spaces. We give a classification result for a special case. In the process of…

Algebraic Geometry · Mathematics 2016-10-25 Toru Tsukioka

Let $(X,\Delta)$ be a projective log canonical pair such that $\Delta \geq A$ where $A \geq 0$ is an ample $\mathbb{R}$-divisor. We prove that either $(X,\Delta)$ has a good minimal model or a Mori fibre space. Moreover, if $X$ is…

Algebraic Geometry · Mathematics 2019-06-04 Zhengyu Hu

In this note, we reduce various conjectures in birational geometry, including Shokurov conjecture on singularities of the base of log Calabi-Yau fibrations of Fano type and boundedness conjecture for rationally connected Calabi-Yau…

Algebraic Geometry · Mathematics 2026-03-16 Guodu Chen , Chuyu Zhou

We prove the existence of a minimal diffeomorphism isotopic to the identity between two hyperbolic cone surfaces $(\Sigma,g_1)$ and $(\Sigma,g_2)$ when the cone angles of $g_1$ and $g_2$ are different and smaller than $\pi$. When the cone…

Geometric Topology · Mathematics 2015-03-19 Jérémy Toulisse

For a toric log variety with standard coefficients, we show that the minimal log discrepancy at a closed invariant point bounds the Cartier index of a neighbourhood.

Algebraic Geometry · Mathematics 2008-11-18 Florin Ambro

A conjecture of Batyrev and Manin relates arithmetic properties of varieties with ample anticanonical class to geometric invariants; in particular, counting functions defined by metrized ample line bundles and the corresponding asymptotics…

Algebraic Geometry · Mathematics 2014-09-23 Brian Lehmann , Sho Tanimoto , Yuri Tschinkel

We compute the minimal log discrepancies of determinantal varieties of square matrices, and more generally of pairs $\bigl(D^k,\sum \alpha_i D^{k_i}\bigr)$ consisting of a determinantal variety (of square matrices) and an $\mathbb R$-linear…

Algebraic Geometry · Mathematics 2019-06-14 Devlin Mallory

Let $X$ be a smooth projective Fano variety over the complex numbers. We study the moduli spaces of rational curves on $X$ using the perspective of Manin's Conjecture. In particular, we bound the dimension and number of components of spaces…

Algebraic Geometry · Mathematics 2019-04-17 Brian Lehmann , Sho Tanimoto

We describe the irreducible components of the moduli spaces of rational curves on Artin-Mumford double solids. This provides the first example of Fano varieties that satisfy Geometric Manin's Conjecture with multiple Manin components in…

Algebraic Geometry · Mathematics 2025-01-17 Fumiya Okamura

We prove the generalised Mukai conjecture for $\mathbb{Q}$-factorial spherical Fano varieties. In this case, a stronger inequality holds featuring an extra term - the minimum absolute complexity of a log Calabi-Yau pair - which measures how…

Algebraic Geometry · Mathematics 2025-12-30 Giuliano Gagliardi , Johannes Hofscheier , Heath Pearson

Fujino and Tanaka established the minimal model theory for $\mathbb Q$-factorial log surfaces in characteristic $0$ and $p$, respectively. We prove that every intermediate surface has only log terminal singularities if we run the minimal…

Algebraic Geometry · Mathematics 2019-02-19 Haidong Liu

We describe the families of minimal rational curves on any complete symmetric variety, and the corresponding varieties of minimal rational tangents (VMRT). In particular, we prove that these varieties are homogeneous and that for…

Algebraic Geometry · Mathematics 2025-05-20 Michel Brion , Shin-young Kim , Nicolas Perrin

In this article we prove that for a large class of 2-dimensional minimal cones (including almost all 2-dimensional minimal cones that we know), the almost orthogonal union of any two of them is still a minimal cone. Comparing to existing…

Classical Analysis and ODEs · Mathematics 2018-08-30 Xiangyu Liang

We describe the moduli space of rational curves on smooth Fano varieties of coindex 3. For varieties of dimension 5 or greater, we prove the moduli space has a single irreducible component for each effective numerical class of curves. For…

Algebraic Geometry · Mathematics 2024-09-04 Eric Jovinelly , Fumiya Okamura

We discuss homogeneity and universality issues in the theory of abstract linear spaces, namely, structures with points and lines satisfying natural axioms, as in Euclidean or projective geometry. We show that the two smallest projective…

Logic · Mathematics 2022-05-27 Wiesław Kubiś , Piotr Nowakowski , Tomasz Rzepecki

In this short note we give a characterization of smooth projective varieties of Picard number one that are separably uniruled but not separably rationally connected. We also give a sufficient condition involving the torsion order and the…

Algebraic Geometry · Mathematics 2019-07-17 Jason Michael Starr , Zhiyu Tian

In this paper, we investigate the minimal length of chains of minimal rational curves needed to join two general points on a Fano manifold of Picard number 1. In particular, we give a sharp bound of the length by a fundamental argument. As…

Algebraic Geometry · Mathematics 2011-04-26 Kiwamu Watanabe

We prove that the Fano variety of lines of a generic cubic fourfold containing a plane is isomorphic to a moduli space of twisted stable complexes on a K3 surface. On the other hand, we show that the Fano varieties are always birational to…

Algebraic Geometry · Mathematics 2011-12-26 Emanuele Macri , Paolo Stellari

We study a divisor computing the minimal log discrepancy on a smooth surface. Such a divisor is obtained by a weighted blow-up. There exists an example of a pair such that any divisor computing the minimal log discrepancy computes no log…

Algebraic Geometry · Mathematics 2017-06-28 Masayuki Kawakita

We prove the ACC for minimal log discrepancies on an arbitrary fixed threefold.

Algebraic Geometry · Mathematics 2024-12-05 Masayuki Kawakita