English
Related papers

Related papers: Okounkov bodies and Seshadri constants

200 papers

For any non-negative integer $k$ the $k$-th osculating dimension at a given point $x$ of a variety $X$ embedded in projective space gives a measure of the local positivity of order $k$ at that point. In this paper we show that a smooth…

Algebraic Geometry · Mathematics 2013-07-12 Anders Lundman

We introduce two sets of invariants for a line bundle at a point: infinitesimal successive minima and asymptotic partial jet separation. They are inspired by the local analogue of Ambro-Ito, and by the jet-theoretic interpretation of the…

Algebraic Geometry · Mathematics 2025-03-18 Mihai Fulger , Victor Lozovanu

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 $e,r \ge 0$ be integers and let $\mathbb{F}_e : = \mathbb{P}(\mathcal{O}_{\mathbb{P}^1} \oplus \mathcal{O}_{\mathbb{P}^1}(-e))$ denote the Hirzebruch surface with invariant $e$. We compute the Seshadri constants of an ample line bundle…

Algebraic Geometry · Mathematics 2024-10-28 Krishna Hanumanthu , Cyril J. Jacob , Suhas B. N. , Amit Kumar Singh

We study families of curves covering a projective surface and give lower bounds on the self-intersection of the members of such families, improving results of Ein-Lazarsfeld and Xu. We apply the obtained inequalities to get new insights on…

Algebraic Geometry · Mathematics 2008-09-15 Andreas Leopold Knutsen , Wioletta Syzdek , Tomasz Szemberg

We introduce higher-order variants of the Frobenius-Seshadri constant due to Musta\c{t}\u{a} and Schwede, which are defined for ample line bundles in positive characteristic. These constants are used to show that Demailly's criterion for…

Algebraic Geometry · Mathematics 2019-05-08 Takumi Murayama

Let $L$ be a nef line bundle on a smooth complex projective variety $X$ of dimension $n$. Demailly has introduced a very interesting invariant --- the Seshadri constant $\epsilon(L,x)$ --- which in effect measures how positive $L$ is…

alg-geom · Mathematics 2008-02-03 Lawrence Ein , Oliver Küchle , Robert Lazarsfeld

This article initiates the study of discrete Okounkov bodies and higher-dimensional Weierstrass gap phenomena, with applications to asymptotic analysis of stability and global log canonical thresholds.

Algebraic Geometry · Mathematics 2025-01-31 Chenzi Jin , Yanir A. Rubinstein , Gang Tian

Let $X$ be a complex nonsingular projective surface and let $L$ be an ample line bundle on $X$. We study multi-point Seshadri constants of $L$ at singular points of certain arrangements of curves on $X$. We pose some questions about such…

Algebraic Geometry · Mathematics 2024-07-19 Krishna Hanumanthu , Praveen Kumar Roy , Aditya Subramaniam

Let $X$ be a complex projective variety, and let $E_{\ast}$ be a parabolic vector bundle on $X$. We introduce the notion of \textit{parabolic Seshadri constants} of $E_{\ast}$. It is shown that these constants are analogous to the classical…

Algebraic Geometry · Mathematics 2023-06-08 Indranil Biswas , Krishna Hanumanthu , Snehajit Misra , Nabanita Ray

We study lower bounds on Seshadri constants at arbitrary points on surfaces with Picard number 1.

Algebraic Geometry · Mathematics 2007-11-06 Tomasz Szemberg

We find lower bounds on the rank of a "real" vector bundle over an involutive space, such that "real" vector bundles of higher rank have a trivial summand and such that a stable isomorphism for such bundles implies ordinary isomorphism. We…

K-Theory and Homology · Mathematics 2025-06-25 Malkhaz Bakuradze , Ralf Meyer

In "Seshadri fibrations of algebraic surfaces" [arXiv:0709.2592v1] we showed that if the multiple point Seshadri constants of an ample line bundle on a smooth projective surface in very general points satisfy certain inequality then the…

Algebraic Geometry · Mathematics 2008-06-10 Wioletta Syzdek , Tomasz Szemberg

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 show the existence of uniformly bounded sequences of increasing numbers of orthonormal sections of powers $L^k$ of a positive holomorphic line bundle $L$ on a compact K\"ahler manifold $M$. In particular, we construct for each positive…

Complex Variables · Mathematics 2015-08-04 Bernard Shiffman

We introduce and study the successive minima of line bundles on proper algebraic varieties. The first (resp. last) minima are the width (resp. Seshadri constant) of the line bundle at very general points. The volume of the line bundle is…

Algebraic Geometry · Mathematics 2020-02-18 Florin Ambro , Atsushi Ito

We characterize those complete K{\"a}hler manifolds supporting a nonconstant real-valued function with critical points whose Hessian is complex linear, has pointwise two eigenvalues and whose gradient is a Hessian-eigenvector.

Differential Geometry · Mathematics 2020-02-21 Nicolas Ginoux , Georges Habib , Mihaela Pilca , Uwe Semmelmann

This paper proves the volume of the arithmetic Okounkov body, constructed from a hermitian line bundle on an arithmetic variety by the author in a previous paper, is equal to the the volume of the hermitian line bundle up to a simple…

Number Theory · Mathematics 2012-01-12 Xinyi Yuan

In this note, we continue the study of Seshadri constants on blow-ups of Hirzebruch surfaces initiated in arXiv:2312.14555. Now we consider blow-ups of ruled surfaces more generally. We propose a conjecture for classifying all the negative…

Algebraic Geometry · Mathematics 2024-07-29 Krishna Hanumanthu , Cyril J. Jacob , Suhas B. N. , Amit Kumar Singh

The global Okounkov body of a projective variety is a closed convex cone that encodes asymptotic information about every big line bundle on the variety. In the case of a rank two toric vector bundle E on a smooth projective toric variety,…

Algebraic Geometry · Mathematics 2011-01-04 José Luis González