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Related papers: Remarks on two problems by Hassett

200 papers

We study the problem of $d$-gonality of the modular curve $X_0(N)$. As a result, we can give an upperbound of the level $N$ by means of $d$. This generalizes Ogg's result on hyperelliptic modular curves ($d = 2$). As a corollary of this…

alg-geom · Mathematics 2008-02-03 Khac Viet Nguyen , Masa-Hiko Saito

In this article, we study the topology and bifurcations of the moduli space $\mathcal{M}_3$ of cubic Newton maps. It's a subspace of the moduli space of cubic rational maps, carrying the Riemann orbifold structure $(\mathbb{\widehat{C}},…

Dynamical Systems · Mathematics 2016-05-19 Pascale Roesch , Xiaoguang Wang , Yongcheng Yin

Motivated by known examples of Joyce structures on spaces of meromorphic quadratic differentials, we consider the isomonodromic deformations of particular second-order linear ODEs with rational potential. We show the infinitesimal…

Differential Geometry · Mathematics 2026-05-22 Timothy Moy

We describe the foundation of the log minimal model program for log canonical pairs according to Ambro's idea. We generalize Koll\'ar's vanishing and torsion-free theorems for embedded simple normal crossing pairs. Then we prove the cone…

Algebraic Geometry · Mathematics 2009-07-10 Osamu Fujino

We find a natural $L_{\omega_1,\omega}$-axiomatisation $\Sigma$ of a structure on the upper half-plane $\mathbb{H}$ as the covering space of modular curves. The main theorem states that $\Sigma$ has a unique model in every uncountable…

Logic · Mathematics 2022-11-29 Boris Zilber , Chris Daw

Using Keel's presentation and Orlov's theorem, we give an inductive description of the derived category of moduli spaces of $n$--pointed stable curves of genus zero and some full exceptional collections in it. The detailed calculations are…

Algebraic Geometry · Mathematics 2012-01-04 Yu. Manin , M. Smirnov

We prove that every Hassett compactification of the moduli space of weighted stable rational curves that admits both a reduction map from the Losev-Manin compactification and a reduction map to projective space is a toric variety, whose…

Algebraic Geometry · Mathematics 2024-09-16 Jasper Bown , Javier González-Anaya

We use Gromov-Witten theory to study rational curves in holomorphic symplectic varieties. We present a numerical criterion for the existence of uniruled divisors swept out by rational curves in the primitive curve class of a very general…

Algebraic Geometry · Mathematics 2020-05-01 Georg Oberdieck , Junliang Shen , Qizheng Yin

The theory of Q-Cartier divisors on the space of n-pointed, genus 0, stable maps to projective space is considered. Generators and Picard numbers are computed. A recursive algorithm computing all top intersection products of Q-Divisors is…

alg-geom · Mathematics 2008-02-03 R. Pandharipande

Let $\mathcal{M}\subset \mathbb{R}^n$ be a compact and sufficiently smooth manifold of dimension $d$. Suppose $\mathcal{M}$ is nowhere completely flat. Let $N_{\mathcal{M}}(\delta,Q)$ denote the number of rational vectors $\mathbf{a}/q$…

Number Theory · Mathematics 2024-07-29 Damaris Schindler , Rajula Srivastava , Niclas Technau

A canonical basis in the sense of Lusztig is a basis of a free module over a ring of Laurent polynomials that is invariant under a certain semilinear involution and is obtained from a fixed "standard basis" through a triangular base change…

Representation Theory · Mathematics 2020-08-19 Johannes Hahn

This work provides the first step toward the classification of irreducible finite weight modules over twisted affine Lie superalgebras. We study all such modules whether the canonical central element acts as a nonzero multiple of the…

Representation Theory · Mathematics 2020-09-30 Malihe Yousofzadeh

Using Moriwaki's calculation of the Q-Picard group for the moduli space of curves, I prove the strong Franchetta Conjecture in all characteristics. That is, the canonical class generates the group of rational points on the Picard scheme for…

Algebraic Geometry · Mathematics 2007-05-23 Stefan Schroeer

This paper is concerned with rational curves on real classical groups. Our contributions are three-fold: (i) We determine the structure of quadratic rational curves on real classical groups. As a consequence, we completely classify…

Algebraic Geometry · Mathematics 2024-08-09 Zijia Li , Ke Ye

There is a proposition due to Koll\'ar 1997 on computing log canonical thresholds of certain hypersurface germs using weighted blowups, which we extend to weighted blowups with non-negative weights. Using this, we show that the log…

Algebraic Geometry · Mathematics 2025-09-03 Erik Paemurru

This is the second in a series of two papers developing a moduli-theoretic framework for differential ideal sheaves associated with formally integrable, involutive systems of algebraic partial differential equations (PDEs). Building on…

Algebraic Geometry · Mathematics 2025-07-11 Jacob Kryczka , Artan Sheshmani

We compute the log canonical thresholds of non-negatively curved singular hermitian metrics on ample linearized line bundles on bi-equivariant group compactifications of complex reductive groups. To this end, we associate to any such metric…

Algebraic Geometry · Mathematics 2020-09-16 Thibaut Delcroix

A Finsler metric, whose holomorphic curvature is bounded from above by a negative constant, is constructed on the moduli stack of canonically polarized manifolds including singularities. Demailly's version of Ahlfors' lemma yields…

Algebraic Geometry · Mathematics 2018-01-24 Georg Schumacher

We discuss the cone theorem for quasi-log schemes and the Mori hyperbolicity. In particular, we establish that the log canonical divisor of a Mori hyperbolic projective normal pair is nef if it is nef when restricted to the non-lc locus.…

Algebraic Geometry · Mathematics 2022-12-27 Osamu Fujino

Using the celebrated Witten-Kontsevich theorem, we prove a recursive formula of the $n$-point functions for intersection numbers on moduli spaces of curves. It has been used to prove the Faber intersection number conjecture and motivated us…

Algebraic Geometry · Mathematics 2013-03-27 Kefeng Liu , Hao Xu