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Related papers: A primer on Seshadri constants

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We establish the existence and uniqueness of twisted exterior and symmetric square $\gamma$-factors in positive characteristic by studying the Siegel Levi case of generalized spinor groups. The corresponding theory in characteristic zero is…

Number Theory · Mathematics 2014-02-18 Radhika Ganapathy , Luis Lomelí

We prove a multiple-points higher-jets nonvanishing theorem by the use of local Seshadri constants. Applications are given to effectivity problems such as constructing rational and birational maps into Grassmannians, and the global…

alg-geom · Mathematics 2008-02-03 Mark Andrea A. de Cataldo

In \cite{nr} Narasimhan and Ramanan and in \cite{desing}, Seshadri constructed desingularisations of the moduli space $M^{ss}_{_{\text{SL}(2)}}$ of semistable $\SL(2)$-bundles on a smooth projective curve $C$ of genus $g \geq 3$. Seshadri's…

Algebraic Geometry · Mathematics 2024-07-26 Vikraman Balaji

In this paper, we use derived sheaves to study rigidity phenomena in the cotangent bundles of manifolds endowed with some locally conformally symplectic ($\frak{lcs}$) structure. Taking inspiration from the work of Guillermou, Kashiwara and…

Symplectic Geometry · Mathematics 2026-05-26 Adrien Currier

The theory of Seshadri stratifications has been developed by the authors with the intention to build up a new geometric approach towards a standard monomial theory for embedded projective varieties with certain nice properties. In this…

Algebraic Geometry · Mathematics 2022-08-12 Rocco Chirivì , Xin Fang , Peter Littelmann

A broadly applicable geometric approach for constructing nef divisors on blow ups of algebraic surfaces at n general points is given; it works for all surfaces in all characteristics for any n. This construction is used to obtain…

Algebraic Geometry · Mathematics 2007-05-23 Brian Harbourne

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

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

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

We introduce a notion of Nakano and Demailly positivity for singular Hermitian metrics of holomorphic vector bundles. Our definitions support the usual H\"ormander and Nadel type vanishing theorems with estimates, at least on essentially…

Complex Variables · Mathematics 2024-01-01 Dror Varolin

This work generalizes the theory of arithmetic local constants, introduced by Mazur and Rubin, to better address abelian varieties with a larger endomorphism ring than $\mathbb{Z}$. We then study the growth of the $p^\infty$-Selmer rank of…

Number Theory · Mathematics 2021-02-09 Sunil Chetty

In this article, we derive bounds for values of the global geometry of locally tessellating planar graphs, namely, the Cheeger constant and exponential growth, in terms of combinatorial curvatures. We also discuss spectral implications for…

Spectral Theory · Mathematics 2008-05-13 Matthias Keller , Norbert Peyerimhoff

We prove that a "cushioned" Hermitian-Einstein-type equation proposed by Demailly in an approach towards a conjecture of Griffiths on the existence of a Griffiths positively curved metric on a Hartshorne ample vector bundle, has an…

Differential Geometry · Mathematics 2021-02-05 Vamsi Pritham Pingali

In this paper we compute the $r$-point Seshadri constant on $\mathbb{P}^1\times\mathbb{P}^1$ for those line bundles where the answer might be expected to be governed by $(-1)$-curves. As a consequence we obtain explicit formulas for the…

Algebraic Geometry · Mathematics 2025-11-25 Chris Dionne , Mike Roth

We prove that an $n$-dimensional complex projective variety is isomorphic to $\mathbb{P}^n$ if the Seshadri constant of the anti-canonical divisor at some smooth point is greater than $n$. We also classify complex projective varieties with…

Algebraic Geometry · Mathematics 2018-10-17 Yuchen Liu , Ziquan Zhuang

In this paper, we investigate the Seshadri constant $\varepsilon(X,T_X;p)$ of the tangent sheaf $T_X$ on a complete $\mathbb Q$-factorial toric variety $X$. We show that $\varepsilon(X,T_X;1)>0$ if and only if the following statement holds…

Algebraic Geometry · Mathematics 2025-07-11 Chih-Wei Chang

In analogy to the relation between symplectic packings and symplectic blow ups we show that multiple point Seshadri constants on projective complex surfaces can be calculated as the supremum of radii of multiple K\"ahler ball embeddings.

Algebraic Geometry · Mathematics 2016-09-13 Thomas Eckl

Let $f : (X, \Delta) \to Y$ be a flat, projective family of sharply $F$-pure, log-canonically polarized pairs over an algebraically closed field of characteristic $p >0$ such that $p \nmid \ind(K_{X/Y} + \Delta)$. We show that $K_{X/Y} +…

Algebraic Geometry · Mathematics 2015-04-28 Zsolt Patakfalvi

Kodaira embedding theorem provides an effective characterization of projectivity of a K\"ahler manifold in terms the second cohomology. Recently X. Yang [21] proved that any compact K\"ahler manifold with positive holomorphic sectional…

Differential Geometry · Mathematics 2023-02-24 Lei Ni , Fangyang Zheng

For an arbitrary-rank vector bundle over a projective manifold, J.-P. Demailly proposed several systems of equations of Hermitian-Yang-Mills type for the curvature tensor to settle a conjecture of Griffiths on the equivalence of Hartshorne…

Differential Geometry · Mathematics 2023-01-24 Arindam Mandal
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