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We compute Seshadri constants of a torus equivariant nef vector bundle on a projective space satisfying certain conditions. As an application, we compute Seshadri constants of tangent bundles on projective spaces. We also consider…

Algebraic Geometry · Mathematics 2021-05-11 Jyoti Dasgupta , Bivas Khan , Aditya Subramaniam

We prove a lower bound on the Seshadri constant $\epsilon (L)$ on a $K3$ surface $S$ with $\Pic S \simeq \ZZ[L]$. In particular, we obtain that $\epsilon (L)=\alpha$ if $L^2=\alpha^2$ for an integer $\alpha$.

Algebraic Geometry · Mathematics 2007-05-23 Andreas Leopold Knutsen

The contribution of this paper is twofold. First, we generalize the definition of discrete isothermic surfaces. Compared with the previous ones, it covers more discrete surfaces, e.g., the associated families of discrete isothermic minimal…

Differential Geometry · Mathematics 2020-03-17 Tim Hoffmann , Shimpei Kobayashi , Zi Ye

In the present note we prove a conjecture of Demailly for finite sets of sufficiently many very general points in projective spaces. This gives a lower bound on Waldschmidt constants of such sets. Waldschmidt constants are asymptotic…

Algebraic Geometry · Mathematics 2017-01-19 Grzegorz Malara , Tomasz Szemberg , Justyna Szpond

Let $X = \mathbb{P}(E_1) \times_C \mathbb{P}(E_2)$ where $C$ is a smooth curve and let $E_1$, $E_2$ be vector bundles over $C$. In this paper, we extend the results in \cite{K-M-R} by computing the nef cone of $X$ without restriction on the…

Algebraic Geometry · Mathematics 2020-03-03 Rupam Karmakar , Snehajit Misra

We provide a lower bound on the degree of curves of the projective plane $\mathbb{P}^2$ passing through the centers of a divisorial valuation $\nu$ of $\mathbb{P}^2$ with prescribed multiplicities, and an upper bound for the Seshadri-type…

Algebraic Geometry · Mathematics 2024-05-07 Carlos Galindo , Francisco Monserrat , Carlos-Jesús Moreno-Ávila , Elvira Pérez-Callejo

In this paper we will propose a new method to investigate Seshadri constants, namely by means of (nested) Hilbert schemes. This will allow us to use the geometry of the latter spaces, for example the computations of the nef cone via…

Algebraic Geometry · Mathematics 2024-09-17 Jonas Baltes

A discrete conformality for polyhedral metrics on surfaces is introduced in this paper which generalizes earlier work on the subject. It is shown that each polyhedral metric on a surface is discrete conformal to a constant curvature…

Geometric Topology · Mathematics 2013-09-18 Xianfeng Gu , Feng Luo , Jian Sun , Tianqi Wu

We present a definition of discrete channel surfaces in Lie sphere geometry, which reflects several properties for smooth channel surfaces. Various sets of data, defined at vertices, on edges or on faces, are associated with a discrete…

Differential Geometry · Mathematics 2019-09-20 Udo Hertrich-Jeromin , Wayne Rossman , Gudrun Szewieczek

The set of volumes of stable surfaces does have accumulation points. In this paper, we study this phenomenon for surfaces with one cyclic quotient singularity, towards answering the question under which conditions we can still have…

Algebraic Geometry · Mathematics 2021-07-06 Diana Torres

Let $X^n_{r,s}$ denote the blow-up of $\mathbb{P}^n$ along $r$ general lines and $s$ general points. In this paper, we focus on $l$-very ample line bundles on $X^n_{0,s}$ and investigate their Seshadri constants with some restrictions on…

Algebraic Geometry · Mathematics 2023-11-06 Rupam Karmakar , Praveen Kumar Roy

Let $X$ be a smooth projective variety defined over a field $k$ of characteristic $0$ and let $\mathcal{L}$ be a nef line bundle defined over $k$. We prove that if $x\in X$ is a $k$-rational point then the Seshadri constant $\epsilon(X,…

Algebraic Geometry · Mathematics 2022-02-17 Shripad M. Garge , Arghya Pramanik

Let $X$ be a projective surface and let $L$ be an ample line bundle on $X$. The global Seshadri constant $\varepsilon(L)$ of $L$ is defined as the infimum of Seshadri constants $\varepsilon(L,x)$ as $x\in X$ varies. It is an interesting…

Algebraic Geometry · Mathematics 2020-02-21 Łucja Farnik , Krishna Hanumanthu , Jack Huizenga , David Schmitz , Tomasz Szemberg

We prove a generalized version of Schmidt's subspace theorem for closed subschemes in general position in terms of suitably defined Seshadri constants with respect to a fixed ample divisor. Our proof builds on previous work by Evertse and…

Number Theory · Mathematics 2019-07-02 Gordon Heier , Aaron Levin

Consider a polarized abelian variety $(A,L)$ over the field of complex numbers. Following Demailly, one can associate to $(A,L)$ a real number $\epsilon(A,L)$, its {\em Seshadri constant}, which in effect measures how much of the positivity…

Algebraic Geometry · Mathematics 2007-05-23 Thomas Bauer

The goal of this note is to study a conjectural picture on lower bounds of Seshadri constants of indecomposable polarized abelian varieties. This is inspired by some ideas of Debarre on the subject and the author's previous work on syzygies…

Algebraic Geometry · Mathematics 2023-12-05 Victor Lozovanu

It is well known that multi-point Seshadri constants for a small number $s$ of points in the projective plane are submaximal. It is predicted by the Nagata conjecture that their values are maximal for $s\geq 9$ points. Tackling the problem…

Algebraic Geometry · Mathematics 2016-02-08 Marcin Dumnicki , Brian Harbourne , Alex Küronya , Joaquim Roé , Tomasz Szemberg

In this paper we consider the question of when Seshadri constants on abelian surfaces are integers. Our first result concerns self-products $E\times E$ of elliptic curves: If $E$ has complex multiplication in $\Z[i]$ or in…

Algebraic Geometry · Mathematics 2019-09-26 Thomas Bauer , Felix Fritz Grimm , Maximilian Schmidt

We investigate the common underlying discrete structures for various smooth and discrete nets. The main idea is to impose the characteristic properties of the nets not only on elementary quadrilaterals but also on larger parameter…

Differential Geometry · Mathematics 2018-02-15 Alexander I. Bobenko , Helmut Pottmann , Thilo Rörig

We explore Seshadri constants associated to weighted blow-ups of complex projective varieties and demonstrate how to use this notion to construct symplectic embeddings of ellipsoids. We illustrate the utility of this point of view by…

Symplectic Geometry · Mathematics 2026-05-28 Jonathan David Evans