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Related papers: Bounds for Seshadri Constants

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The existence of a Seshadri stratification on an embedded projective variety provides a flat degeneration of the variety to a union of projective toric varieties, called a semi-toric variety. Such a stratification is said to be normal when…

Algebraic Geometry · Mathematics 2025-09-03 Rocco Chirivì , Xin Fang , Peter Littelmann

We give the first examples of nef line bundles on smooth projective varieties over finite fields which are not semi-ample. More concretely, we find smooth curves on smooth projective surfaces over finite fields such that the normal bundle…

Algebraic Geometry · Mathematics 2007-12-14 Burt Totaro

We observe that if we are interested primarily in degeneration arguments, there is a weaker notion of (semi)stability for vector bundles on reducible curves, which is sufficient for many applications, and does not depend on a choice of…

Algebraic Geometry · Mathematics 2019-08-15 Brian Osserman

We prove that projectivity is an open condition for deformations of algebraic spaces with rational singularities. V.2: references updated and corrected.

Algebraic Geometry · Mathematics 2021-05-25 János Kollár

This paper presents a novel methodology for evaluating the boundedness, stability, and instability of some vector nonlinear systems with multiple time-varying delays and variable coefficients. The proposed technique develops two scalar…

Dynamical Systems · Mathematics 2024-08-26 Mark A. Pinsky

Given a closed subscheme $Z$ of a polarized abelian variety $(A,\ell)$ we define its vanishing threshold with respect to $\ell$ and relate it to the Seshadri constant of the ideal defining $Z.$ As a particular case, we introduce the notion…

Algebraic Geometry · Mathematics 2025-05-12 Nelson Alvarado

Separation bounds are a fundamental measure of the complexity of solving a zero-dimensional system as it measures how difficult it is to separate its zeroes. In the positive dimensional case, the notion of reach takes its place. In this…

Algebraic Geometry · Mathematics 2024-05-31 Chris La Valle , Josué Tonelli-Cueto

In the context of quantum gravitational systems, we place bounds on regions in field space with slowly varying positive potentials. Using the fact that $V<\Lambda_s^2$, where $\Lambda_s(\phi)$ is the species scale, and the emergent string…

High Energy Physics - Theory · Physics 2023-06-13 Damian van de Heisteeg , Cumrun Vafa , Max Wiesner , David H. Wu

For smooth projective curves the Clifford index is an important invariant which provides a bound for the dimension of the space of sections of a line bundle. This is the first step in distinguishing curves of the same genus. In this paper…

Algebraic Geometry · Mathematics 2009-10-12 H. Lange , P. E. Newstead

Let $X$ be a general hypersurface of degree $md$ in the weighted projective space with weights $1,1,1,m$ for some for $d\geq 2$ and $m\geq 3$. We prove that the Seshadri constant of the ample generator of the N\'eron-Severi space at a…

Algebraic Geometry · Mathematics 2020-12-07 Alex Küronya , Sönke Rollenske

In this paper, using Klyachko's classification theorem we study positivity and semi-stability of toric vector bundles on a class of nonsingular projective toric varieties, known as Bott towers. In particular, we give a criterion of $s$-jet…

Algebraic Geometry · Mathematics 2019-04-09 Bivas Khan , Jyoti Dasgupta

Let $X$ be a smooth projective complex variety of maximal Albanese dimension, and let $L \to X$ be a big line bundle. We prove that the moving Seshadri constants of the pull-backs of $L$ to suitable finite abelian \'etale covers of $X$ are…

Algebraic Geometry · Mathematics 2020-09-07 Luca F. Di Cerbo , Luigi Lombardi

In the present sequel to our previous two papers on regularity on abelian varieties, we give a number of new applications of the theory of $M$-regularity to the study of Seshadri constants, Picard bundles, pluricanonical maps on irregular…

Algebraic Geometry · Mathematics 2007-05-23 Giuseppe Pareschi , Mihnea Popa

In this paper we derive sharp lower and upper bounds for the covariance of two bounded random variables when knowledge about their expected values, variances or both is available. When only the expected values are known, our result can be…

Probability · Mathematics 2021-06-21 Ola Hössjer , Arvid Sjölander

We give a sharp lower bound for the selfintersection of a nef line bundle $L$ on an irregular variety $X$ in terms of its continuous global sections and the Albanese dimension of $X$, which we call the Generalized Clifford-Severi…

Algebraic Geometry · Mathematics 2015-11-03 Miguel A. Barja

In this article we prove new results on projective normality and normal presentation of adjunction bundle associated to an ample and globally generated line bundle on higher dimensional smooth projective varieties with nef canonical bundle.…

Algebraic Geometry · Mathematics 2019-09-10 Jayan Mukherjee , Debaditya Raychaudhury

A stratified bundle is a vector bundle which is a D-module. We show that regular singularity of stratified bundles on smooth varieties in positive characteristic is preserved by pullback and that regular singularity can be checked on…

Algebraic Geometry · Mathematics 2015-03-18 Lars Kindler

In this paper, we give complex geometric descriptions of the notions of algebraic geometric positivity of vector bundles and torsion-free coherent sheaves, such as nef, big, pseudo-effective and weakly positive, by using singular Hermitian…

Algebraic Geometry · Mathematics 2021-03-17 Masataka Iwai

We prove that certain vector bundles over surfaces are ample if they are so when restricted to divisors, certain numerical criteria hold, and they are semistable (with respect to $\det(E)$). This result is a higher-rank version of a theorem…

Algebraic Geometry · Mathematics 2023-11-15 Indranil Biswas , Vamsi Pritham Pingali

We study the positivity of exterior powers of the tangent sheaf on toric varieties in order to generalize results by Campana and Peternell about 3-folds with nef second exterior power of the tangent bundle. Using the theory of equivariant…

Algebraic Geometry · Mathematics 2018-11-08 David Schmitz